civ IV BTS or Complete

I already have civ 4 Vanilla and I was wondering is their a difference between bts and complete. which one should I buy? Also, when will civ 4 comlete be out in the USA

Complete is with Warlords. If you want to play Warlords Scenarios.
Complete has only 1 DVD, so you don`t have to change DVD's to play Vanilla / Warlords/ BTS.

Is warlords only scenarios? As in if I got BTS would that have all the new features of Warlords plus the new ones?

BTS includes all of warlords and more so that's all you would have to install. Warlords technically isn't only scenarios but effectively it is as BTS has all of those changes and much more. You should just buy BTS.

so i should not wait for civ 4 complete to come out?

I can't believe CC did such a lousy job explaining the differences to you, this topic has only been brought up 18 times in the last month!

BtS has all the game features included in Warlords. The only reason to get Warlords is if you also want the scenarios. Most people feel they're not worth it, but no one denies the appeal of the Barbarians scenario, in which you get to be the Barbs, destroying all the civs, so you may want it for that.

If there are any important code changes to C4C, I don't know what they are, but I do know that, frex, the Steam version of Civ4 requires different patches. It is PROBABLY perfectly safe to get C4C, but if you have lingering doubts, hopefully someone knowledgeable will answer that.

On another note, did you intentionally misspell Ozone Layer?

Ok I got it, im getting civ 4 bts cuz i never do the scenarios. BTW I did misspell layer. Im gunna keep it that way though cuz I sound like dr evil with my ozone "lair".