I'm kind of mad I just found this thread. I'm currently in my second year at the University of Maryland.
I absolutely LOVE this school. For me, it's perfect. The location is great. The campus is located 9 miles from DC, so students often go there for a night out or during the day to chill. Most of the clubs in DC are 18 to get in, 21 to drink, so you'll be fine. Annapolis is also about 30 minutes away (it's a beautiful, historic, waterfront city). Baltimore is 45 minutes away. If you're looking for a school in a populated area I think Maryland is your best choice.
The University has about 35,000 students, of which 25,000 are undergraduates. There's a ton of international students just because we are so close to DC. The school is very diverse and pretty liberal. We also have one of the largest Jewish populations of any school in the country. The school is almost 1/3 Jewish.
As for the social life, it couldn't be better. If you like to party, Maryland is the school for you. Everyone drinks. Sports are huge here, too. Particularly football, basketball, lacrosse, and soccer. We consistently have one of the best soccer and lacrosse teams in the country and games are so fun to go too. I'm just assuming you have an interest in soccer since you're British, but soccer is big here. The games are very well attended and one of the most fun things to do on campus.
The academics are also good. We're consistently ranked as one of the best values in public education in the country. Our engineering, journalism, and business programs are particularly good.
Here's a video of the school, showing some of the campus, the lacrosse game against Duke, and of course the partying (which is the focus of the video):
http://www.youtube.com/watch?v=HgmRhFV3OrwHonestly, how could you not want to come here after watching that video? Jk, but seriously, this school is incredible and I highly recommend it to you.
Oh, and I forgot. Our campus if effin' beautiful. We have the longest collegiate mall in the United States. And last not but not least, our alumni do big things. Some famous alumni include Jim Henson, creator of The Muppets (he actually created The Muppets for his major here), Larry David of Curb Your Enthusiasm and Seinfeld fame, Sergey Brin (one of the co-founders of Google), the guy who created Under Armour went here, Carly Fiorina (former CEO of Hewlett-Packard), one of the co-founders of Sirius Satellite Radio, and the list goes on and on.
I keep thinking of more reasons why this school is awesome. The DC metropolitan area is the wealthiest and most educated part of the country. I wouldn't want to live anywhere else.
Also, if you're into music, the DC music scene is exploding right now. So many great concerts, venues, and artists are coming out of the DC area.
So, yeah. You should go to MD. PM me if you want more info.