Guitar Hero and Rock Band are hot topics these days, and for good reason. I even recently created a Guitar Hero parody. The original explosive hit, "Guitar Hero" turned thousands on to the rhythm game genre. Guitar Hero II followed close, but then something happened. The talent behind the Guitar Hero series was too powerful to stay as one entity- Activision bought RedOctane, and MTV bought Harmonix. RedOctane went on to produce number three of the Guitar Hero franchise, while Harmonix took the idea a step further with a new game, "Rock Band."

I own both, I've played both, and I felt the need to weigh in on the matter. I've broken it down by category below, so let's get this underway:

Set List
Arguably the most important aspect (other than gameplay itself) of a rhythm game. If the songs suck, it's not very fun to play. Guitar Hero III weighs in with 71 tracks (29 bonus) while Rock Band gives us 58 tracks (13 bonus). GHIII has more songs but a higher ratio of bonus songs, while Rock Band has a few more "known" songs. A majority of the tracks from both games are based on the original masters, a nice change from GHII. As for the songs themselves, preference is completely a personal choice. For me, I like RB's list a lot better. They both cover the same genres and have overlapping artists (and even a few tracks) but RB seemed to always go with the better choices in my opinion. The classics found in GHIII are good songs, but they're the ones I'm tired of hearing on the radio- Talk Dirty to Me, School's Out, Hit Me With Your Best Shot, Welcome to the Jungle, and so on. RB has the classics that I still want to hear, like Don't Fear the Reaper, Tom Sawyer, Wanted Dead or Alive, and others. I also found a lot of the newer tracks on RB more enjoyable, while ones on GHIII I hadn't heard of or didn't like very much. RB has one big thing going for it though: when you play songs in multiplayer, you come across songs that might not strike you as good, but your friends really like them. And as such, you end up liking them too. While with GH, you're usually playing by yourself, or with less people.
Winner: Rock Band

Gameplay
Rock Band is kid of hard to compete with in this category, for the lone fact that you can choose between drums, mic, and guitar. Guitar Hero of course only offers you guitar and bass guitar. As for the game engines themselves, both perform fine. Hitting the notes still felt comfortable in both games after coming off of GHII, with no slowdown in either. GHIII has a noticeably larger timing window for the notes, which makes Hammer-ons and Pull-offs easier. That's nice, but to compensate, they cranked up the difficulty level too. More on that later. Gameplay really isn't an issue with either of these games, but I do have a couple things to nit-pick at GHIII about. First, and this only applies to xbox users as far as I know, the achievements are kind of lame. Do we really need an achievement for beating the game on lefty-flip mode? That's just annoying. And when you beat the game on expert, you still have to do it on hard, medium, and easy to earn all the achievement points. RB finally fixed this by giving you all the points for beating the game on expert. RB has a better star power(excuse me, 'overdrive') system too, in the sense that you can continue gaining power even while in overdrive mode. It's something I've always wanted in the GH games. Plus, overdrive in RB looks cooler. GHIII lessens the 'impact' of deploying star power from the previous installments and makes it feel generic. You'd see what I mean if you played it.
Winner: Rock Band

Difficulty
This is the area most open to controversy. It's no surprise that Guitar Hero II ramped up the difficulty significantly from the first one. As a result, GH players sort of formed an elitist 'club' as I like to call it. Suddenly beating the game on hard or even expert weren't accomplishments anymore, you had to five star songs like Hangar 18 on expert. And if you could last through Jordan on expert, you were god. This holds true with Guitar Hero III, with songs like Devil Went Down to Georgia(non-battle mode) and Through the Fire and Flames. I don't have much input on the matter, since I can't come close to beating them on the hard difficulty levels. Does that want to make me practice? Not at all. The amount of skill and practice required to beat songs like these start to make the game not very fun anymore. I feel as though I've hit a wall in my Guitar Hero skills, and increasing them further doesn't enthuse me. Rock Band on the other hand, is more laid back. Rock Band's expert mode is more equivalent to GHIII's hard mode. I guess that doesn't make it as 'hardcore,' but certainly more fun. I'll practice a little to get through Green Grass and High Tides, the hardest guitar song in RB, but I really don't feel like beating myself up trying to master the ridiculous sequences in GHIII's Raining Blood. A lot die-hard GH fans will continue to keep their elitist attitude about the difficulty level, but for me RB is just right.
Winner: Rock Band?

Graphics
As far as I'm concerned, Rock Band trumps Guitar Hero III in both graphics and overall design. The character models in GHIII are noticeably better than GHII, but that's about it. The venues seem very generic looking and uninspired, especially the 'music video' one. And while the main characters sure look cool when they play the guitar on stage, the rest of the band looks like a robotic orchestra, synced to their obvious cue points in the songs. Load up Rock Band, and the difference is immediate. ALL of the characters play their instruments with fluid movements, giving off a human persona vibe. They sway and move around the stage, have idle animations, and just look like they're really into the song. The game uses many 'filtered' camera effects which are right at home here. Stuff like adding grain, turning the screen black and white, etc, give it a more dynamic feel. Then venues and the effects in them also look much better, making you almost feel like you're at a show. Neversoft really dropped the ball here.
Winner: Rock Band

Characters
If it weren't for Rock Band's character customization options, this category wouldn't even exist. In Guitar Hero III, you're limited to a set collection of characters. Some of which are pretty cool, like the Grim Ripper and God of Rock. You know what's even better though? Creating your own. RB doesn't exactly have extensive options when it comes to character creation, but it's not too hard to make something that resembles yourself pretty well. Then there's the clothing wardrobe, which offers almost endless options to dress your character up with. I'm not really into the wardrobe thing that much, but it's nice to have a selection. Unfortunately RB runs into one big flaw here, in fact it's the one thing I truly don't like about this game: characters must remain with the instrument you create them with. If you design a character to play on drums, they will ALWAYS play the drums. This is very annoying when you want to play multiplayer mode and switch instruments. Also, in RB's Band World Tour mode, the creator of the band must always be present. That's fine, but it's linked to the actual character, not the person (you) that made them. So even though I created the band under my gamertag, the guitarist that I started it with must always be present too, even if someone else wants to use their guitarist. A glaring oversight as far as I'm concerned. GHIII gets points here just for being easier to manage.
Winner: Tie

Multiplayer
Rock Band has nearly swept the categories so far, and this one is a no-brainer. Playing Rock Band with a full four-person band simply can't be beat, and the Band World Tour mode emphasizes that. Guitar Hero multiplayer tends to become very competitive, all about who can nail the raddest solos. GHIII offers battle mode but it's very random and unbalanced, leaving little to actual skill. Of course there's co-op mode too, and you get some new songs for it, but what about when you're done? Band World Tour in RB is nearly endless, and makes it more fun for everyone as you play shows, earn money, and gain fans. Does someone who isn't very good at guitar games want to play? Stick them on the mic and they'll still have fun. And you'll have more fun as everyone hits the notes and sings the songs together, instead of showing everyone how well you can beat GHIII's hardest tracks on expert mode. BWT mode isn't online, but it's not an issue as far as I'm concerned, it's still plenty fun by itself.
Winner: Rock Band

Final Verdict: Rock Band, no contest
Rock Band is a great game that excels in almost everything it tries to do. Why no love for Guitar Hero III? GHIII is still an excellent game, but it simply can't compete with something new and original like Rock Band. RB is worth it just for the drums, as you may have heard already. You may have also heard that Rock Band is only better if you're going to be playing with friends. Not for me. Playing the solo tour on drums is more fun than guitar, because it's a new experience. So that, along with my reasons above, make Rock Band my game of choice.