RTS:
- Most older Command & Conquer games (Red Alert, C&C, Generals/ZH, Tiberium Wars)
Red Alert 2 and its expansion are by far my all-time favourite games.
- Starcraft & Starcraft II
- Warcraft I, II or III.
- Knights & Merchants (old favourite of mine. Not very well known... more of a guilty pleasure). Medieval army building. strategic placement of units, their composition and use of terrain is key here. 'Gold' is not so much an all-round commodity in this one. You need to harvest trees, farm animals and craft and smith weapons to supply and feed your army with. Cool stuff, and the soundtrack's very cheerful and fun.
Like AoE:
- Rise of Nations
- Civilization (although it's more turn-based and the games are very lengthy).
- Stronghold and Stronghold Crusader
- One of the many 'Total War' games. Very in-depth, lots to it.
Leveling and 'lootwhoring':
- Borderlands. Very enjoyable, tons of interesting weapons, characters, skill-trees and ways to play.
- Farcry. Very good worldbuilding. Lots of exploration.
- Torchlight. Amusing for a while.
- Any of the Elder Scrolls games. Arena, Daggerfall, Morrowind, Oblivion and Skyrim. Very easy to spend thousands of hours on any of these games.
- Crysis. [insert meme here]
- RSCRevolution. lol 
- Prototype. Amazing open world action-adventure game where you 'evolve' into all kinds of crazy shit. loved this. Not sure about its sequel. Feels like Spiderman
flying around the city causing mayhem. Not so much about loot, but you yourself evolve into a deadly weapon.
- Pillars of Eternity. Much like Diablo III. Ode to Baldur's gate and old classic RPG-games. I don't have much experience with this one.
Hope there's something for you in here