I find it’s always a matter of personal taste, and have frequently been underwhelmed by highly rated games that just aren’t my style. You may want to take a peek at metacritic.com
My faves include Picross DS, Advance Wars DS, Lost in Blue I and II (which critics hated). I also liked Freedom Wings, which is impossibly hard and not well liked. NY Times Crossword gets super hard. Age of Empires offers lots of gameplay like Advance Wars, but the interface is slower. Also, you may want to pick up one of those board game collections. You’ll get good use out of them when you’re not in the mood to play something that requires a lot of time and concentration. I like Boggle/Yahtzee/Battleship/Monopoly, but there are others to choose from. Club House games is supposed to be a good value in that regard, but I’ve never played it.
Now’s a good time to buy, though because with so many new releases, there’s bound to be something good.
How is Zelda?