Does it have to be RPG, or can it be an eroge featuring 'gameplay'? Anyway, my favorite RPGs:
Toushin Toshi - It's availible for free, get the prepatched version, then apply the fanpatch(fixes many issues). Same universe as Rance, and it's also canon.
Toushin Toshi 2 - Also my favorite, improves on the original in many ways, but it's more a spiritual sequel and it's own universe\setting, not part of the Rance or original one. Also freeware, get the prepatched version, then apply the fan patch.
Brave Soul - Diablo like combat, and multiple romance options(no harem iirc), what's not to like?
Bunny Black - A bit darker(contain some forced content). party based turn based RPG, the
Sequel is just as good, sadly the third game was never translated.
Men at Work 2 - Another one of my all time favorites, story is ok. Multiple romance options(though you need to clear previous routes to access further options\routes etc, only 2 heroines can be romanced the first playtrough) and a turn-based combat.
Utawarerumono has a great story, but it is the definition of linear(choices make no difference at all, only one path).
Tear s of Tiara - Same as the previous one, good story, but completely linear with only one ending.
Seinarukana -The Spirit of Eternity Sword 2- Not actually played this one, though I played the prequel(which has no adult content in the english release). Story in the first one was pretty good(if not a bit clichè), so if this is anything like the prequel, then it'd be a great story, with branching endings\romance choices. The combat is more automated though.
Beat Angel Esclayer Reboot - Can turn glasses on\off. Combat is kind of action-paced turn based iirc. Though most scenes are focused around the main heroine.
Daibanchou -Big Bang Age- - Kinda like Sengoku Rance, but a different universe(more a school theme iirc).
Kingdom(in english translation) - Not really an RPG, more a dating sim. Lots of different paths\romance options(a bit buggy sadly). This is just overall one of the games that got me into HGames(With gameplay, I can't stand VNs).
Duel Savior - Figthing game. Story is ok(a bit too clichè for me), protagonist is very hit-miss. Like Men at Work 2, you need to clear previous routes to unlock further routes(start with 2 options, after clearing both you're given either 1 or 2 more). Feature a light leveling up mechanic, but it's primarily a figthing game.
I have plenty more(all english translated, either fan or officially localised), but the post is already gotten pretty long, lol. So I'll leave it at that.