Bartre wrote...
(luminous arc 3 has been confirmed? What.)
Shin Megami Tensei: Devil Survivor
Valkyrie Profile is pretty good, it's in a vein similar to FFTA.
Suikoden Tierkreis is decent, but far too easy. But I still put in about 50 hours, so all is well.
Harvest Moon/Rune Factory It's a farming sim, which doesn't sound all that awesome on paper...but in practice... It's addicting, the DS games haven't really filled the N64's version shoes, but they aren't bad.
Super Robot Taisen OG Saga: Endless Frontier is snarky, and it has amusing characters...and Kaguya. It wins.
The World Ends With You is pretty innovative(relatively speaking) and it has adjustable difficulties, which you can access on the fly. Combat was fun, if unwieldy sometimes as the AI is about as dumb as rocks, especially on higher levels. (You can cheese it by making their defense really high though).
There are like 100 Dragon Quests if that's your thing, and Final Fantasy is always a good choice.
Just do yourself a favor, and get Tetris DS. If you take anything from this post, take TETRIS, DO EET NAO.
(yet another edit): For original games, try Rhythm Master and Bangai- O Spirits. The former is exactly what it says on the tin, the latter is pretty much bullet hell...a lot of bullet hell.
Is it complicated because I read a guide on marriages and god my head turned upside down >.<