I'm looking at buying a empire building game to waste some time till the h5 expansion get here & i want something thats like sim city but has a combat aspect. It doesn't have to new either, just good.
The only game i know of like this is settlers II, which i have, so i was thinking of getting the 10th anniversary edition which also looks pretty good.

So any recommendations? is there something better to get? I'm totally out of touch with what games theres is of this type.

edit:
oh yeah, and my computers not that great, so preferably something thats not gfx heavy.

There are lots of games of that type, it depends on whether or not you want a more combat orientated or city building type.
The older Settlers series, the ones that the S II 10th anniversary are based on offer a bit of both and are very cheap now, but not all expansions are available, if you want more combat, then Settlers 5 is more mainstream RTS, again quite cheap now. If as you say you have a less powerful computer than you'd like, it might be best to stick to slightly older games, which also have the advantage of being on budget release now.
Others to consider are the Age of Empires series, the Stronghold series, Lords of the realm, Rise of Nations, etc.

Having played very little of the Settlers and not being very good at it. (BTOG will agree ) I can only recommend Age of Empires, for me it's the best there is.

I didn't like any of the age of empires series. Multiplayer they were awesome, me and my brother used to have massive wars on age of empires 2 with the expansion. But singleplayer was soo boring.

Also im not looking for a RTS, ive got plenty of them, but more something where you build a city with economics & such... something like sim city.

If you aren't all that bothered about combat, how about something like the Caesar series of games, or Children of the Nile, virtually pure city building games with some trade and not much combat.
They focus on economy and efficient town planning, and since you mentioned it, Sim City itself is worth trying, it just depends on whether you want a modern, or would like a historical setting.
A good place to look is this site, City buildin games they have a wide range of games and demos , they even have free to download City Building games.
Have fun.

fantasy tbs + (little)empire building:
-dominions 1&2
-age of wonders 1,2&shadow magic

the true original:
-civilization 3
-alpha centauri

in space:
-space empires 4&5
-galciv 2