Oh man. I am in a serious hole here. Idk what I'm gonna do.
I currently own Guitar Hero III: Legends of Rock, Guitar Hero: Aerosmith, and Rock Band for Wii. My family all likes the Guitar Hero guitars better, but then, we already have a guitar, drums and a mic for Rock Band, since they came along with the game. We do have two Guitar Hero guitars btw, we got one with each game.
And now Guitar Hero: World Tour is coming out in October, and for Wii we have Rock Band 2. Both are confirmed to have downloadable content, multiplayer online, all that good stuff. World Tour will have Mii Freestyle and more importantly, create a song though. No word on which will have more graphical power between the Wii versions.
So the question is: which will come out on top? It seems from this side of the releases that Guitar Hero does better work on the Wii than Rock Band. Guitar Hero also has create a character already guaranteed, and you can use the usual Guitar Hero characters (create a character doesn't mean with the Miis- that's a separate mode all its own). Rock Band 1 didn't have any characters, or creation either. But Rock Band 2 might have the full prowess that was put into the 360 and PS3 versions of the Rock Band games. Both have damn good track lists.
So it seems I should pick one direction or the other, not both. We're starting to waste money if we invest in both. With both Guitar Hero games that I currently have, I have 110 songs, give or take. With Rock Band, I have 60ish, and haven't bought the track pack for the other 20.
Seems to me I should stick with Guitar Hero. Again, my family likes the guitars better, we can already tell that there's lots of effort involved with the Wii exclusives, and I have two of the instruments.
Rock Band isn't guaranteed create a character and we're not as used to the guitars, but I have three of the instruments.
And here's the other issue: the instruments aren't compatible. The Wii Guitar Hero games all use a Wiimote to work alongside the instrument, including the drums, which have a spot to plug it into above the drum pads. Rock Band doesn't. Instead, it uses just one for the mic.
I only have two Wiimotes, so I'd have to buy two more and get drums and the mic for Guitar Hero. With Rock Band I just need one guitar.
So what do I do? I'm thinking I'm gonna go with Guitar Hero because they even put modes in exclusive to Wii, and seem to care about the system more- probably because GHIII sold a zillion units on Wii. But then it's a larger investment- two instruments and two Wiimotes that I'm not sure my parents would enjoy buying. On the other hand, they bought more than half of Rock Band, and they bought both Guitar Heroes all on their own 
And then, I should probably get two more Wiimotes anyway...
I think I'll sell the games from whichever franchise I ditch. Meaning selling both Guitar Heroes or Rock Band on ebay, where they sell for twice what I bought them for lol. Sound off if you have a suggestion- Guitar Hero or Rock Band, Wii versions. Thanks!