I keep hearing DS XL and 3DS XL are worth it with the larger screen but I just kind of felt like they were over priced.
They are a bit pricey, but if you search for one around the holidays, you can get a 3DS XL for less. In past holidays, I've seen the XL sell for $150 at a few retailers, and there was even a time where Target was clearancing out older colours for $99.99. I prefer to play on a TV too, but the XL is good enough to be worth it I feel.
Well, Pokemon HeartGold and SoulSilver are enhanced remakes of some of the best games in the series, but I'd say a better comparison would be with OmegaRuby and AlphaSapphire.
This is probably true, however I have not played one of those games either, and don't own one, so I compared it to the game I did play on 3DS. There are still some things I liked in HeartGold that did not make a return in X, such as having a Mon follow you around. However, the best thing about HeartGold is that it had online co-op for the Battle Frontier! It was actually a lot of fun, and this feature is not in X/Y nor ORAS. I also own Platinum on DS and I'd probably place that ahead of X as well since it still has the Battle Frontier, but I didn't like its world as much as the world in X.
I have not yet tried Pokémon Super Mystery Dungeon, but I did get a copy over the holidays so I hope to try it soon. I'm a bit confused about how rehash-y it might be however, as I've heard it contains the same areas as the previous games. What does that mean exactly? No idea. Have to try it and see.
Here is a link to my DS collection page on GameFAQs. It includes a few DSiWare also, can't filter that out.
Unfortunately, I still have not played a lot of it, so I'm not very good for recommendations just yet. I've also played some of the more popular games, like Advance Wars, Castlevania, NSMB, Tetris DS, etc., that people have already played, though I'd recommend them to anyone who still hasn't! Some more games I liked were:
-Dragon Quest V: Pretty old school by design, but it's got a great story and interesting world to explore.
-Picross 3D: Fantastic puzzle game with a lot of puzzles, a unique and tricky concept. I've always liked 3D puzzle games but there aren't very many of them. Looking forward to the sequel on 3DS!
-Etrian Odyssey: Old-school dungeon crawler. The original is still one of my fave DS games, though there is a remake on 3DS. I actually own it, but have not played it, so I can't speak to if it's better.
-Planet Puzzle League: A solid version of this match-three-or-more puzzler, but probably less unique now with phone games. I still want a new version on 3DS though!
-Rune Factory 1 & 2: Mixing Harvest Moon with a dungeon crawler? Sounds awesome, and it is! Tending to the farm is more rewarding when I can buy new weapons with my hard-earned cash and go beat up some beasties. I haven't played 3 or 4 yet, but I do own 3.
-Super Princess Peach: Probably questionable with its motives, but it still has some unique gameplay and I enjoyed exploring its levels.
I also liked Phantasy Star 0, but, not worth playing with the online gone.
Most of this is probably stuff that most people have heard of or played, but still, good stuff!