And here are my favorites as of 18.5.2014
I made two lists however. The first list contains 6 games which I would play and recommend even today, the second list consists of 10 games which have a place in my heart but which I would not necessarily play today or recommend to a modern gamer.
I also don't take MMOs into the list.
Favorite "modern" Games:
Jagged Alliance 2 (in a version supporting a resolution of 1024 x 768)
One of the very few games I come back to again and again. I love the 60+ characters with their individual personalities, likes, dislikes and traits. Love the humor and most of all, the turn based combat system
Avernum: Escape from the Pit
Gigantic game with the hardest fights I have seen in RPGs yet. Tons of great written dialogues which don't come with walls of text. Several choices with impact on the story. Tons of changes in dialoges after events happened not seen in bigger games. Weakest point: Horrible background loops (can be disabled), no music
Dragon Age: Origins (Excluding the Ostagar DLC and the Expansion which was horrible)
While I dislike the combat system, (realtime with pause) which forced you to pause every 1/2 seconds or so, this game had great storytelling, though the choices felt rather gamey than realistic.
Drakensang: River of Time (Excluding the Expansion as well)
Also had a bad combat system (realtime with pause) with different problems than Dragon Age. In this game the aggro system works quite bad making a big mess out of combat. But it offers a great atmosphere and story.
Mass Effect 2
Another Bioware game with great storytelling. Combat works but isn't particularily outstanding. Stuff which didn't work in ME1 was cut/simplified. Most of the fun are the dialogues and the situations which can happen (e.g. bringing Legion to Talis Ship)
Fallout 3 New Vegas
Though I prefer the Setting and Story of Fallout 3, this game has the better game and quest design. Still, the non-retroactive skill system bothered me. This game offers tons of interesting quests and choices. But while you had to look up Skyrims quests in a Wiki due to bad quest design, you had to look up F3 NV quests in a wiki due to being bugged so often. But I played at release and guess that's fixed already.
Old Games:
Jagged Alliance 1 & Deadly Games
Again tons of characters with own personality, traits, strengths and weaknesses. Like in the first game (compared to JA2) that you had to fight in all sectors, the sneak-sectors were great and loved the daily recap. Deadly Games was a Multiplayer version of the game with further developed characters where you could start an campaign against/with another player and could create your own maps. However a great Deadly Games experience only comes with own maps and plaid with a friend.
Stonekeep
Simply one of the most atmospheric games I played. Otherwise a linear Dungeon Crawler. Was nice to only control the main character and let the party members do their thing. Also had several situations with nice
humor.
Lands of Lore 1: Throne of Chaos
Love the westwood style of graphics and sound. Great mix of "Dungeoncrawler", Story and places to explore.
Realms of Arkania 1, 2, 3 (German Versions, no idea which changes were made to the English ones by Sir-Tech)
If I had to chose one, it would be the second game StarTrail. First game offered a huge world you could freely explore but the world itself wasn't too detailed. With the 2nd and 3rd part the detail went up, and the size went down until the 3rd game shadows over Rive was completely linear. The second game StarTrail is a nice compromise. The luck based character system felt horrible though and coted tons of lime for save/load spam.
Fallout 1 & Fallout 2
Free, open world, turn based combat, postapocalypse. What can you want more? If I had to chose I would go for Fallout 2. Just overall bigger and better.
Elder Scrolls 2: Daggerfall
Horribly buggy game but it felt like being in an actual digital, huge world, where you could settle down in a town no other player in the world actually might have visited yet. Also liked the big and difficult dungeons - if they weren't as broken.
Albion
Did a great job to immerse you in an alien world. Great atmosphere, the turn based combat was also quite decent as far as I remember.
Planescape Torment
Also very atmospheric and very deep texts in a very unique setting. In comaprison to BG it completely focused on the story, had no problems with the combat system here.
Might and Magic 4+5: World of Xeen
Big world which was very fun to explore. Quite colorful game with it's own whacky humor.
Dark Sun 1: Shatered Lands
Quite atmospheric game in a very unique setting. Fighting as slave in the arena alone was quite entertaining. Nice turn based combat system. I also remember it as one of the first/ oldest games I played with Dialogues and Choices ("Why did you kill him???" - "I was in mood for it…")