Yeah, I rarely make friends in games. Even my closest friends in games, I will turn on if the opportunity is right. I've been playing a lot of Europa Universalis and Civilization 4, and I absolutely refuse to make nice with my neighbors. For Civ4, I tend to first focus on religion or economy if I'm isolated. I get a few holy cities/religions under my belt, then I start focusing on religious buildings and Wonders that relate to religion, such as the building that unlocks all Religious civs. Once I encounter my first 'friendly' civilization, I begin to nurture them into a military powerhouse. A) Because the final battle will be glorious that way, and B) Because that way I can focus more on other things. After I slowly conquer the world through either culture or dominating with my military alliance, I then turn on my original partners and have an epic global war. If they haven't quite lived up to my expectations, or I haven't focused enough on military, I go into World Builder and give us a shitload of nukes.
In the end, I just like seeing great things fall. It's not about conquering as much as it is about destroying. I really enjoy seeing a huge empire go from a grand military powerhouse to a wimpering puppystate that wants peace. I think a quote from Watchmen is somewhat valid here. 'All the whores and politicians look up and scream, "save us!", and I'll look down and whisper, 'No.'. That's gaming power, man.
Normally in Civilization, I only build up enough military to fend off my neighbors' attacks while I work toward a science victory. I rarely betray my allies, but if they backstab me (and they usually do, because I move quickly to cut off their expansion), I don't stop until they I have crushed them.
In Civ I always played the nice guy, conquering only where necessary and more or less focusing on the scientific victory. Sometimes I force myself to be the aggressor with no friends, and I think that's a bit more fun, even if you end up feeling like a jackass when you nuke Paris and the whole world declares war on you. In Total War, the game eventually will get too easy and you have to make an effort to be fighting enough people fighting you to present a challenge. There's nothing particularly fun about playing the game without combat, and it won't win you the game, so.
Yeah for CIV for the 360, I build my empire for awhile,gold and science, and when a leader acts like an ass or starts war i tend to kill everything. I also played a lot of Rome total War, and i liked it, but they just always push you into war. You'll have like one turn of peace and then they pop up behind your city attacking.