OGame, perhaps? 

Is Ogame one of those online games where you have to wait in real time over hours/days for things to build/troops to move/etc.?

Cosmic Supremacy looks pretty interesting, I will definitely check that one out, thanks!

There is MP, but this not a cloud game or an MMO (if thats what your looking for)...

Was just playing....  The Battle for Wesnoth!!!!!!!! 

Top notch game.  I'da been happy paying $60+ for it.  Buts it's free.  Always has been.  Its a gem of an open source project.  I'm as hooked on Wesnoth as I was on Civ. It's fantasy turn based strategy.  It comes with many campaigns comprised of individual scenarios.  There is a wide variety of races in the game.. elves, dwarves, humans, dragons, zombies, skeletons, merpeople, wraiths, liches, goblins, orcs, ogres, griffins, ++.  And there is magic of course.  Units level up and have traits and special abilities.  The campaigns that come with the game are well done.  The art is top notch.  There is a wide variety of terrain and enviroments to play in.  The game runs fast and secure even on the PC I'm currently stuck with... an old thing that doesn't even have a dedicated graphics card (will run Civ3 but not Civ4). The game is fully modable.  Many well created campaigns are available for download from within the game.  Some mods incorporate a gun powder age and space age.  Some mods are RPG based.  Others allow for special weapons and items.  Its a high quality fun game.  The mods make it eternal.  Also includes an exceptional map editor.  In many ways this game should serve as a standard for quality PC gaming.  I HIGHLY recommend The Battle for Wesnoth!!!  Oh, and the game supports MP and there is a large and active MP community.  The AI also does a great job (due to time restraints I play SP only and am quite happy with the AI). 

That's pretty much why I stopped playing Ogame as well.  When you're getting up in the middle of the night solely to check on your planets (and making sure they're not under attack), something has definitely gone awry. 

+1 Wesnoth. It's a truly great game. A triple A title and open source to boot. The multiplayer lobby is generally buzzing.

There is also TripleA, an Axis and Allies clone which, I believe, has online play.  Also free.

it comes with an editer, if thats what your asking.

Battle for Wesnoth is more of a story/campaign game though, rather then a game where you fight the computer with equal numbers on an equal map. So any sandbox/random map mode is definitely not how I'd recommend playing it. It's still a great game though and something you should try.

You can also try Ministry of War. It's a free to play browser strategy MMO. You pick a civilization (Egypt, Rome, etc), and build up your cities. There's PvE (roaming monsters, lairs with bosses for loot), and 2 kinds of PvP: arenas, where you can sign up your hero (heroes command armies, level up, have skills, equipment, stats, etc) and get exp and fame for winning and you can get some equipment from that. Then there are contested zones, which open up for fighting at set times (usually evenings), for civ vs civ mass PvP and territory control. The kicker is: in MoW, you actually can fight the tactical battles (both PvE and PvP), instead of seeing a stat report from the auto-resolve like in the other browser games. You load a battle map, command your units, have your hero use abilities, etc. There is still automatic if you don't want to fight manual, but it's a bad idea for arenas where if you go auto and the other guy goes manual, well There's research, trading, "religion" (think culture/border spread, some things you can only do within your own borders), and it looks good.

http://ultracorps.sjgames.com/

Needs a lot of fresh blood.  Well I've bailed on it mostly because the community is a bit stagnant at the moment, but the game is still fun, and still free.

If you do poke your nose in there tell them licker sent you.  Though maybe if you want to be treated decently you shouldn't mention that bit...

I have played Wesnoth off and on for a couple of years.  Sandbox mode is kinda lame.  But thje campaign has many. many, tactical challenges.  And they are not extremely difficult - but not easy, either.  And the variety of challenges, and varied mix of units is - well, a great ride.  

You could try out Atlantica Online, it's free to play, excepting that there is a huge pay to win component as you approach level 100 and beyond.  Loved the game, but they [Nexon] has the most offensive cash grab that I've experienced in an MMO via their Item Mall.

silly me, I never noticed the posting date.  Three years, I am slow!!!!!  ROFL.  Guess I should stay off the threads evenings when i am having a nice glass of wine before settling in for the evening?