Honestly, I am not sure how to divide my favorite games since I mostly play ARPGs and RPGs but at the same time they don’t exactly feel like they are in the same genre. So, here is my try at distinquishing them.
Fantasy ARPG - The Witcher series, hands down. Elder Scrolls is close but Witcher beats it at every aspect, imo.
Post-apocalyptic ARPG - Fallout New Vegas. Only played it and 4, so can’t talk about the whole series.
Diablo-clone - Titan Quest: Immortal Throne. Despite how much smoother and quicker the action is in GD I just love TG more overall because of the mythology and setting. The epic journey is just that epic :x
Turn-based RPG - Divinity Original Sin 1&2. Very fun, great world. Hoping for a 3rd one.
Action-adventure - GTA series. God, I played most of it, even Stories. Have very fond memories, especially about SA.