Yeah, Sonic Advance 2 would be a good one to get, but be warned: a lot of the game's special features, including the Tiny Chao Garden and the Sound Test, are unlockables: you have to get all the Chaos Emeralds with a single character to unlock each feature. It's still quite a fun game, though, and I personally don't regret buying it. (I have everything in it unlocked now, including the super-cool Super Sonic battle at the end, even though I did need some help from GameFAQs in finding some of the Special Rings.)
Other good options include Sonic Advance + Sonic Pinball Party (two Tiny Chao Gardens in one game!) and Sonic Advance 3 (no Tiny Chao Garden this time, but it has character voices, a unique tag team gameplay arrangement, and other cool things in it. (Unfortunately, SA3 is also the only Sonic Advance game I completely finished without GameFAQs help.)
P.S. I also figured out that Hyrulian was LZR. Having to keep up with several name changes at KRR Forums made me good at this. :)