There has been a surprising amount of great HD versions of games popping up on the iPad side of the App Store lately. If you've been playing some of these games pixel doubled, or have been waiting for a native iPad version to pop up, any of these games are definitely worth downloading:
Across Age ™ HD, $4.99 We liked the original Across Age a lot in our review, and really consider it a must-have for any fans of Zelda-like games. The HD version is home to some incredibly detailed hand drawn art, and even a new dungeon (and boss) exclusive to the iPad.
Baseball Superstars® 2010 HD, $0.99 I can't get enough of the Baseball Superstars games, as the light RPG elements combined with arcade-style baseball makes for a package I can't stop playing. Check out our review for more details, but beware, getting involved in this game could suck up a dangerous amount of your time if you're like me and enjoy filling experience bars.
ARKANOID HD, $4.99 You don't get much more classic than Arkanoid when it comes to brick breakers, and while we liked the iPhone version a lot, single device multiplayer works really well on the iPad. If you're looking for a blast from the past, or another fun two player game, give this a shot.
Meow Meow Happy Fight HD, $2.99 This has been one of my favorite iPhone dual stick shooters since it was released in August. The iPad version looks great, and is much nicer to play with proper iPad controls instead of playing the iPhone game pixel doubled.
Cut the Rope Original HD, $0.99 I gushed over the iPhone version of this game in a big way in our review, and the iPad version is just as good. There isn't much sense in re-buying this as it plays fine pixel doubled... But the graphics do look awfully nice on the iPad screen.