Which forms?

Which forms are you supposed to fill out for taxes as a US citizen living in the UK?

1040
W-7
1116
2555
Schedule A
Schedule B
6251
TD F 90-22.1
4868 or 2350
P86
SA100
SA101
etc etc

well I used to file a 1040ez in the us, I cant do that anymore now can i?

I think the point Guya is trying to make is you have asked a question on par with "how long is a piece of string." 

You have asked an incredibly broad question, which has actually been covered in a number of threads and then you want a specific answer for free from a guy who gets paid to do this.

You are going to have to get your hands right in this to know what you need. Or hire a professional.

I would start by doing some research here:

http://www.usembassy.org.uk/irs/index.htm

The FAQ is pretty useful.

There are also tons of threads here. You need to figure out your situation before you can figure out what forms you need to fill out. The IRS also publishes guidelines for tax payers abroad, which you can download from their site (along with any forms you will need).

well I used to file a 1040ez in the us, I cant do that anymore now can i?

No idea, but I am a UK citizen who lived and worked in the US last year and I have to file forms 1040NR-EZ (NR is Non-Resident alien... i.e. people on a US visa) and 8843  . I'm glad that I don't have to worry about any of the other forms that guya listed, because I don't think I could handle any more of them !