well higurashi na naku koro ni was already mentioned, but i'd also throw in umineko, since same writer, and overall awesome.
other than that, Megaman Zero (fav to least fav: 3,1,4,2), Azure Striker Gunvolt (the entire series except Luminous Avenger iX2 since i haven't played it yet), Cave Story (the fact that it's free is one of the least impactful selling factors, i think you could sell it to anyone while saying it costs 60 dollars), Deltarune and Undertale (you don't say) and Hotline Miami 2: Wrong Number (peak relaxation imo). I think that's about it in terms of like FAVORITES favorites. But I'd also say Castle Crashers (just don't play it enough) and Rogue Legacy are also really good.