I really enjoyed (and still occasionally play) Russian developer Playrix's Call of Atlantis on the iPhone. It's a pretty straightforward match-3 game that nevertheless has a lot of appeal. Somehow, the pieces (including some weird-shaped boards), certain items that you need to release from the grid to match up and some special power-ups are tuned just right so that I find it more fun than most games of the type -- it's almost as great as PopCap's own Bejeweled. And now, the company has released the next game in the series, Rise of Atlantis as an HD version on the iPad.
It's worth checking out, especially if you're in the mood for an iPad-specific match-3 experience. The graphics and colors are vibrant, and like Call of Atlantis, there's a very loosely connected "story" mode to go through with 77 different levels to beat. And you can even go back and beat them for a high score if you're into that. There's no multiplayer or achievements or anything, unfortunately, but then again, a solid match-3 game is just a game where you sit on the couch and flip little icons to match them up by yourself -- and is there any better device for a game like that than the iPad? I think not.
The Mac version of the game was spotlighted by Apple, and this one should be popular as well. You can try out the lite version for free, or pick up the full iPad game for a launch sale price of US $4.99.