Oblivion and Skyrim are both a ton of fun. I got on the Elder Scrolls train a little late, so I don't know about any of the Elder scrolls games before those. Both of these titles are completely different animals though, in terms of how some of the basic mechanics work.

Oblivion's magic system is very complex. The list of spells probably spills over into the hundreds, if not thousands, due to being able to mix and match spells. It was a bit too complex for me, personally. Also, I seem to remember needing torches for caves in this game. That was kind of neat. If you like an RPG-heavy experience with questing and magic and swords n' stuff, it's a good buy. Also, the modding community is amazing.

Skyrim has much more simplified magic. There are much fewer spells here in terms of number, but it managed to retain a good deal of variety as well. No more mixing and matching spells for combo spells, but I had a great time playing a mage. It also got a great graphical upgrade from Oblivion, especially when it comes to the design of some of the races, Khajiit (cat race) and Argonians (lizard people) in particular. Crafting in this game is pretty cool as well and the modding community is equally as amazing as Oblivion.

Dark Souls is the kind of game that chews you up and spits you out and while you're curled up on the ground crying, it proceeds to kick you. For some odd reason, I just keep finding that motivating. It's probably one of the hardest games ever created, but it feels so good when you progress. I've had this game for 2 years and have still never beaten it. You play as an Undead looking for your lost humanity. This leads you on your pilgrimage to collect souls and destroy evil, mainly in the form of rattling skeletons, giant rats, and big demon guys with clubs that are about 100 feet tall.

If you like MMOs, but don't want to pay a monthly subscription fee, I'd really recommend Guild Wars 2. Not only does it only require a 1-time payment or somewhere around $50, but it's very well polished and offers a variety of really cool armor and items that you can get without being level 80-something. Spell-casting in this game is really fun and aesthetically pleasing, but the melee classes are a sight to behold as well. The environments are incredible and vibrant and I've never found my self senselessly level-grinding on pigs in a forest, like so many other MMOs. This game focuses on group events that anyone can participate in instead of repeatable quests and level grinds on ordinary mobs. You can start participating in these events with friends and strangers alike as soon as level 2 or 3 instead of having to reach some middle range level before you've even able to survive. Guild Wars 2 also allows you to convert your in-game coins into currency that normally would have to be bought, allowing even people who don't have enough real money all the time to access premium items, like new character outfits and mini pets.

If you liked the idea of Elder Scrolls, but didn't want to play in medieval times, this might be for you. Fallout is a game steeped in moral choices and character relationships. The wasteland is a vast place, teeming with life, loot, and wonder to behold. Character progression is unique, thanks to the setting being in and near post-apocalyptic Washington DC. This is not your average RPG; that's apparent from the very moment you start playing.

If you've gotten in on the "survival sandbox" craze, which it sounds like you have, these are both good examples.

7 Days to Die is a zombie-focused game that uses voxels for terrain and structure blocks. Despite that, the game looks very polished and aims for realism. Your main concerns in this game are food (which must be cooked at a camp fire or you risk illness), water (which should be boiled at a camp fire for best results), food storage (keeping smelly foods or uncooked meats on your person attracts zombies), and noise (you can attract the dead and spawn hordes if you make too much noise). This game also offers array of crafting recipes for furniture and building blocks and items like couches, guns, scopes, crossbows, tea, burn cream and much more.

Rust recently had its zombies removed, so I'm not sure what the devs plan to do to fill that void, but it's a great game. It doesn't use voxels like 7D2D, so the building is much more like that of Gary's Mod, which is fitting considering it's developed by the same person. This game is very survival heavy, dropping you in the wilderness naked with only a rock. Avoiding bears and wolves is only one of your problems. You must gather wood to create a shelter; gather stone and ore to make tools, items, and gunpowder; loot surrounding irradiated buildings for guns, armor, or other spare parts for crafting; and keep yourself warm. Depending on if you're playing alone or depending on what kind of server you're playing on, you might also have to worry about other players knocking your door down with C4. I personally don't play on PvP servers and the game is still a great co-op experience with friends.