What handheld console?

I think the ps vita.

All factors will have to be taken to affect.

Well let's list these two points for this area.
Wii U is not a handheld console but a home one so let's get that out of the way.
3D's XL is the same thing as the original console just a bigger screen so could have said 3D system overall.

Now to the main points.
- The internet browsers differ as ps vita has more html5 support than the 3D's.
- System layout. When playing games I feel way more comfortable using two joysticks rather than one which the 3D system has. Sure the 3D's can go buy and attach a second joystick but the design looks weird after.
- Price Range wow that differs the vita system costed me way over 300 bucks so 3D defiantly wins this round.
- Apps well all I can say I like the Vita's way more than 3D's. Facebook and Paint for me.
- Games I'm not saying they're aren't any good ones both systems have excellent games.

3D's has great games from several different series such as Fire Emblem, Pokemon, Mario, and several other titles

The Vita brings bigger franchise such as the Persona series, resistance, call of duty, little big planet, katamari, killzone, tales of, hatsune miku and many others but the list itself would get crowded. Plus games downloaded from PSN you can also access PS1, PSP, and PlayStation Mobile games.

Overall from my experience I had more joy using the vita system than the 3Ds. Got since launch date and been using it ever since. Plus pretty hand when it comes to waiting for your professor to arrive to class

The 3ds is the best console ever hands down. Streetpass and spotpass is amazing as well as the games such as Mario kart and super Mario 3d land as well animal crossing is coming out!
Best console ever

If by handheld you mean one to take around with you, then definitely pick one of the 3DS's, if you mean one that you can hold in your house, then either Wii U or 3DS's.

The Wii U is not one that can be taken away from the console. The GamePad just acts as a separate, differently displaying screen and also a controller. It offers an amazing social network, and new ways to play with asymmetric game-play.

The 3DS is better for playing with your friends, as it currently has more online games, a brilliant free application called "Nintendo Letter Box" (Or SwapNote in the US) and a StreetPass system in which if you carry your 3DS with you as you walk around, if someone else has theirs nearby you will both get free items in different games that the other person has. Neither of you lose these items so I take my 3DS with me _everywhere_ I go.

Hope this helps you.