I loved both Hero of Kendrickstone and The Lost Heir. (Which is on topic since they’re both games I’d recommend). They’re both very similar thematically. A fantasy setting where you become an adventurer, starting off completely inexperienced but slowly growing in power. You have a choice of mentors, and a number of careers you can choose from. And they’re both crying out to be trilogies.
Choice of Robots seems the obvious game to suggest, since it’s sci-fi like Mecha Ace. It’s also like no other Choice of game. It’s immense in scope and complexity. If there’s just one game you can buy I’d say buy that one, since it’s hugely replayable and you’ll certainly get your moneys worth.
I enjoyed Thieves Gambit: Curse of the Black Cat. It’s a fun heist game. Psy-High’s good as well.
I haven’t played any of the recent hosted games apart from The Lost Heir so I can’t comment on those.