Regular New 3DS no doubt, has higher ppi, coverplates and it's more portable.
I have a New 3DS XL and it just looks awful.

Still waiting for Nintendo to announce a black new 3ds though, i don't like the white one...

I'm looking into buying a regular N3DS just for the faceplates, greatly improved startup and loading times for both the system and it;s games, improved web browser, slightly better graphics here and there along with a slightly more refined look to it and I totally dig the improved 3D viewing which will allow me to make better use of that feature.

Unless you really want a bigger screen or a bigger handheld to grip, i'd go with a regular new 3DS, for the reasons everyone else has stated

Also for games these are the must haves:

Kid Icarus: Uprising
Luigi's Mansion: Dark Moon
Zelda: A Link Between Worlds
Fire Emblem: Awakening
Smash 4 3DS

If you haven't played N64 Zeldas the 2 ports are great


Dragon Quest 7 & 8 are coming this year too, amazing JRPGs.
Bravely Default is pretty good, and Hyrule Warriors Legends has fun gameplay and it's a huuuuge game.

With more than 5 years on the market, the reason is easily for the games.There are many awesome games on it, and with the price of 100 - 120(if you look hard enough) dollars for a 3DS, its the best time to buy one.Awakening, Luigi Mansion, Bravely Default, Zeldas, Dragon Quests, Mario, Fates, KH, Professor Layton, Phoenix Wright, Shovel Knight.The list goes on and on, and the games I listed are far from being the only excellent ones.Spo yeah, buy one and you wont regret it.

Go with an N3DS XL, with all the 9.5 rated games you can not go wrong.

Just wait until we know if NX is 3DS-compatible.

Seems like a horrible time to invest in a Nintendo product with them releasing new things really soon, I would wait for the unveils of their new products.

If you don't have a 3DS, it's best to go with the new one. It's an overall improvement on the model, and you have the extra stick for camera control and easy smashing in... Smash. Unless you don't like the large size and don't have access to the regular new 3DS, then just go with the older classic. There is issues with the screen getting lines on it, due to the bottom part pressing on it.

None, get a 2DS