If you are going into Classical Archaeology DO NOT APPLY TO UCL FOR NEXT YEAR (10/11)!!
I applied for this program and was invited for an interview. After going all the way to London (I was in Europe at the time so it wasn't quite as far as the states but it still was an extra journey that I would have happily avoided) I was told by the department members that I met with that I was accepted into the school, but that the program in Classical Archaeology was not being offered this year! So I had to sit there for about an hour as they tried to talk me into going to their general Archaeology program even though they had almost no course offerings related to Classical (specifically Roman) archaeology, besides like a classical art class. I thought this was very underhanded of them and also reflected on what I think is the general feel of that school. UCL may have a global reputation, but I don't think that it is necessarily adhering to those same standards anymore.
Anyways, long story short if you are planning on doing anything with Classical Archaeology at UCL, their website is wrong, the program is NOT being offered, and as far as I know they won't let you know this until you get there since even in email form they referred to my application as for the program in classical arch.
This is not to say, however, that all British universities are bad. I am going to the University of Exeter next year to do my MA and then reapply in the states. The only thing I would be really careful of is that if you do decide to do an MA in the UK is that you take language modules even though they are not required because PhD programs in the states will be looking at those. But I say look at the facility and students and see who is doing the kind of work that you want to be doing. I didn't choose Exeter just because I wanted to get an MA done quick, I choose it because there are some people that that I am extremely excited to work with, which I think is probably one of the most important things when choosing a grad program, after money of course.