I've got plenty, but if I had to pick just one? We Cheer 2.
No no. Seriously. I picked up the original We Cheer practically on a dare and it ended up being one of the best games on Wii and one of the few that uses the Wiimote well (there's alot of smoke and mirrors involved but hey! It WORKS!). However that thing, believe it or not, had a STEEP learning curve that made ALOT of people think it just didn't work. Me? I 100%ed the thing.
We Cheer 2 though? WOW. They went ALL OUT on that sequel. Totally redid everything, added TONS of customization, new modes, ect. Best of all they added a new Easy mode, and lowered the difficulty on Normal mode...and then kicked UP the difficulty on Hard! So crazed We Cheer veterans like myself still have a rock solid challenge!
As for how it plays? Well...it's kinda like Elite Beat Agents except for Wii and with motion controls. You hold one Wiimote in each hand (yes, two Wiimotes. Nunchuck cord is too short. You can play with one Wiimote too though), arrows appear on screen indicating the kind of motion you need to do and you do it, essentially dancing along with the cheerleaders in the background. Each song has it's own unique choreography and there are no canned motions.
Some videos:
All Goth Squad: http://www.youtube.com/watch?v=KISNiPKFb3M
Elite Beat Divas: http://www.youtube.com/watch?v=w0NSbBMsYf8
(Yeah, the character customization is kinda awesome)
My crappy video reviews of them:
Samba de Amigo vs We Cheer 1: http://blip.tv/file/2819538
We Cheer 1 vs The World: http://blip.tv/file/2819616
We Cheer 2: http://blip.tv/file/2928350
*ahem* Yeah. Sorry. Long post. Just...I think saying "We Cheer is one of the best things on Wii" demands some explanation, don't you? XD