here are the games that I've picked out, but i don't know what to do...
Mario Bros
The ledgend of Zelda
Cue Sports: Snooker Vs Billiards
ROTOHEX
Cubello
Orbient
currently i'm more towards Cue Sports...
Defend Your Castle, if you don't have it.
If you do, Mario or Zelda.
Super Mario Bros 2 Lost Levels is pretty fun.
I'd pick one of the Art Styles, based on your list. Cubello and Rotohex are alright, but Orbient is the best, imo. All up to preference.
Super Mario Bros. 2 is a good game to play for about 15 minutes a day. But it's also very challenging, so it'll last you for a while. =P
I've got SMB: LL already ;)
I've been thinking about Art Style ever sence they came out on WiiWare, but i really want a game that will last me long, will Art Style keep me busy for a while, or is just a side game?