I would recommend the vita.

I have played both even though i only own the vita it just seems of better build, quality of graphics are great, ps+ as some have said already and the games are more to my tastes.
Having said that the 3ds seems to have a better future, BUT its still worth the risk and investing in a vita.

3DS: I prefer the gameplay I can find on this platform.

this is gonna be interesting. but to answer your question as turkish said, its the vita because it has better games for turkish

We'll see, I would list AC III: Liberations as one of the bigger selling points of the Vita which is distinctly not 1st party

3DS is the obvious contender. More good games already out, sucessful system, with great software already announced to be released with great support from Japan garanteed since it s ahuge hit there. You cant go wrong with it.

Once you have one, you might want to consider getting a Vita aswell if you want.

Depends if the OP is asking for a recommendation of one or the other or simply asking which is better.  Only 4 of the 9 games you listed in the OP are available outside Japan.  While it's no doubt a good list, if he's looking to get one of the consoles this Christmas (for example), pointing out that Dragon Quest VII is coming out next year on a region-locked console isn't much use to him.

It is kind of a vague OP though.

On topic: 3DS, but not for the reasons people have been listing.  I don't think the 3D is a particularly interesting feature and I don't think by any stretch that circle pad is better than Vita's analogue sticks.  But it has the software at the moment, and at the end of the day that's all that matters.

I bought my Vita because WipEout + LittleBigPlanet + Gravity Rush was what I wanted over Nintendo's offerings and I'm loving it so far.  But for Joe Public, I'd imagine the 3DS offers a much better library.  Look at the games which are there and decide which is better for you.

3DS - it has a wide variety of interesting games, and big games like Zelda, Fire Emblem, etc. are certainly on their way. Vita has fewer games, and a more limited variety. If you like only sports, action, and console ports, go for Vita. (I don't care for such things) Plus the 3DS costs less.

3DS.
Access to the entire DS library plus more games than PSV

I'm really surprised this thread hasn't completely blown up yet.

Right now, I would say the 3DS because of the support, and games.

The Vita isn't a bad choice either, but the waning 3rd party support, and expensive ass memory cards ($25 for 4GB???))

In the near future though, the Vita would look like a good buy.

vita.

because you have a sly cooper avatar therefore i can say with 100% confidence you'll prefer vita's library of games.