Could anyone recommend a good 4x game?

For a fairly in-depth turn-based 4x game, did you ever try Galactic Civilizations 1 and 2...?

Huge tech trees and lots of room for micro management.

It's basically what Master of Orion 3 SHOULD have been. Good graphics, stable gameplay, and loads of potential for wasting hours upon hours.

That game is actually solely responsible for burning an image right into my previous LCD monitor. I was playing the damn thing for so many hours non-stop, that over the course of several days, I burned an image of the game's interface right into my monitor.

I'd also recommend Galactic Civilizations 2. I loved the ship aesthetics customization and the tech trees. It's available on Steam now too. There's always Civilization V if you are looking for a semi-historical one. The new expansion looks to add a lot of cool options if that's your thing.

There's a new game coming out soon(ish) which I discovered on KickStarter, its called Star Drive. Might be worth checking out if you like space empire building / exploration / combat style games.

If you want something a bit retro, have a look at Alpha Centauri, which you can pick up for a few bucks on www.gog.com. :)

If you liked Masters of Orion and Ascendancy (which were both awesome, IMO) there's a good chance you would like Endless Space. I also second the recommendations for Galactic Civilizations I + II, both were excellent games, though I thought GalCiv 2 was the better of them. I had been looking for a good 4x game myself, and I personally like the sci-fi/space themed games the best. Ascendancy is one of my all-time faves, and Alpha Centauri was really good as well.

endless space kinda sucks to be honest, the tech tree just seems bad, whole game is pretty simple. i started like 1000 games and after 15 minutes I was overwhelmed with boredom.

Warlock master of the arcane is pretty crappy too, movement on the map is extremely slow. would have been better if it was homm style.

oh and random mob spawning on near my capital city, surounded by 5-6 other cities, killing my elite lvl 1000 unit with 2 hp which was on the retreat made me ragequit.

master of orion 1 for example, started 1000 games and they lasted 8 hours :))

galactic civ 2 is awesome

if you don't mind playing old games, Imperium Galactica II totally rocks ^^