Well, I've searched long and hard for quality titles - and I did find some decent stuff back when I had my iPod Touch.
So far, my favorites:
Galaxy on Fire 2 HD
Space Miner HD
Starbase Orion
The Room (pretty damn cool)
I've yet to find a quality RPG that can get even close to something on PC - and that includes older titles like Baldur's Gate.
There are some decent action RPGs - and Dungeon Hunter 3 HD is pretty cool, if you're just looking for straight-up loot/killing. But it's also extremely shallow and 100% about making you buy stuff in their store.
I'm tempted to try out Avernum and Avernum 6. They look like actual RPGs - but my experience with the older Spiderweb PC versions have not been good. Avadon, for instance, wasn't really my thing.
I tried that turn-based Cthulhu game - but found it extremely simplistic and underwhelming.
There's a decent X-Com clone called Aliens vs Humans - but I found the interface awkward and uncomfortable.
The Quest is still a great Wizardy-lite - but it looks like someone threw up, unfortunately. It was better suited for Pocket PC or the Touch. I wonder if The Legacy (from the same developer) is available? Hmm.
Undercroft is OK - but ultimately quite shallow.
Aralon - the "TES" type game is like taking a modern TES and taking it 15 years back in time. After having played something like Skyrim - I really don't see the point in playing something like this. But I guess it does serve to prove that it's not impossible to make something decent on the platform, eventually.
I've tried dozens of other games, but I forget the names. Angry Birds is a very competent clone of the ancient games in the same style. Those games where you had to aim a cannon from a distance by inputting numbers and praying. The genre evolved over the years - and something like Worms is probably the ultimate evolution of it. I don't understand why Angry Birds is getting praise for being a completely derivative clone of a completely derivative clone - but I guess people are easily impressed. But it's definitely well done.
Same goes for Plants vs Zombies - which is one of the best Tower Defense clones. But it's still just retreading of an archaic formula - handled really well with good production values. Again, people either didn't grow up with the same games I did - or they just have a short memory. Well, that, or they like playing the same crap over and over and over.
Oh, there is this Movie Quiz app that I forget the name of. It's VERY good. I really like that one.
Other than that, though, I find myself underwhelmed - but the amount of titles out there is ENORMOUS. We're talking thousands of games.
One day, I'm sure there'll be a truly good and unique RPG which is suited for the platform.