Really didn't care much for TWEWY either and ended up quitting around the end of the second week (I believe there's 3). I hear it's only 10 hours long if you don't bother to do any additional grinding, so I'm sure I could boot it up right now and finish it a few hours later, but I really can't be bothered. Like you I thought the story was alright but I just didn't care much for the gameplay.
Anyway, here's a few of my recommendations:
Alice in Wonderland
Great stylus-driven platformer that absolutely no one knows about, but trust me on this.
Kirby: Canvas Curse
Easily my favorite Kirby game, and probably the only line-guided platformer that's actually good.
Dragon Quest IV, V, VI, IX
If you like traditional turn-based RPGs you can't go wrong with either of these.
Final Fantasy III
Same as the above, pretty much.
Dragon Quest Monsters Joker 2
Depending on what it is you don't like about Pokemon this might not be for you, but it's a quality game and so much better than the first Joker.
Kingdom Hearts 358/2 Days
A total must-play if you're already familiar with the series, but if not you probably shouldn't bother with it.
Lufia: Curse of the Sinistrals
If you want Zelda, just play this instead -- it's so much better.
Dragon Quest Heroes: Rocket Slime
Same as the above (though it's not nearly as puzzle-driven as Zelda and Lufia).
Touch Detective 2 1/2
This is my favorite adventure game on the DS but it's a bit of an acquired taste. If you can't look at some gameplay and go "man, I really like the graphical style, music, characters and surreal humor" it's probably not for you, because gameplay-wise it's just a standard PC-style point 'n' click.
Solatorobo: Red the Hunter
Just an all-around great action RPG (and if you're into anthropomorphic animals I guess that's a plus), though you need to be able to tolerate the extremely low difficulty.
Rune Factory 3: A Fantasy Harvest Moon
If there's things about Harvest Moon you like but you've never been able to stick with it for long because there's no action and it goes on forever, then this game's for you.