Gothic series.
Gothic 1 & 2 are easy recommendation and are, at the very least, really good.
Gothic 1 is great and was extremely fresh for its time (one of the 1st RPG's that I've seen w/ full-on voice-acting, NPC schedules, NPC's doing immersive stuff, etc etc - which I think a lot of games like Skyrim took); and Gothic 2 is really good.
Gothic 2 feels like "more of the same", but much-much bigger as a game. I also felt a lot of the problems I had w/ Gothic 1 were less forgivable (i.e. awkward controls, main characters' voice-acting being recycled, etc) b/c they should've advanced things by the time the sequel came out.
I'm probably in the minority here, but I prefer Gothic 1 - I loved the setting of the penal colony within the barrier and its whole premise. Gothic 2 is really good, mind you - but it all really feels like set-up for G3, by the time the game ends (by the end of the base-game). For me, G1's abrupt ending felt more promising & more impactful.
Gothic 3 is good overall, but had a bunch of issues out-the-box, back in the day. It's in WAY better shape, since the Enhanced Edition. Definitely going to want to get that all patched-up. It's also much bigger in size & scope than G1 and G2 - though, some of the questing isn't as choice-laced or decisive-important as previous titles (this feels more Elder Scrolls-like and less Gothic 1-like) and also future titles (i.e. such as Risen series and ELEX).
Advice - make quicksave especially and/or manual saving your friend fast. You can walk in the wrong direction/path and in no time get slaughtered here. These games ain't easy by any means, so use your smarts when moving around. Usually, higher-level enemies make sense in these games and are logical - as they'll often be much bigger and/or much taller than you; like trolls and golems. Trust me, you see one in the distance - QUICKSAVE NOW. And, well...if you're low-level, you might wanna go a different path/direction.
I still have G3: Forsaken Gods backlogged; and Arcania and its expansion backlogged...all which were NOT made by Piranha Bytes (PB).
For me, it's often very easy to recommend PB's games (Gothic 1-3; ELEX; Risen 1-3): they all are good at least and very similar in many ways and sometimes different in others (often the setting is the real difference). It's just, you're goin' to often have to get around some jank, clunkiness, and difficulty to get into their games. Some just seem to have less jank, difficulty, and/or clunkiness compared to others (i.e. this seems to improve more & more w/ each title).
In the long run - I think it's worth trying to get around their minor issues to play their stuff. They're usually at least good and solid.
over the panic buyers.
