The 3DS has gone through a massive turnaround phase that's lasted almost a year now. It's all thanks to an awesome crop of new and compelling software and a satisfying combination of price and functionality from the 3DS XL.
The PlayStation Vita has become an indie gaming mecca in the past year or so, cashing in on dozens of inexpensive and addictive titles that also cross over with the PS3. A new Vita is likely to hit soon, so be sure to watch for the likely-to-fall price of the current system.
The 2DS won't win any awards for its looks, but it's probably the best portable console out there for the younger gamer in your life, thanks to its interesting slate-wedge design. Just be sure you buy a protective case along with it.