Personally, I would recommend getting an Apple (but that's just me since I have a 12'' Powerbook). However, you might run into problems with that since most Law School Programs run only with Windows. For example, NYU requires students to only have a Windows machine. Luckily, Berkeley, in general, adores Apple computers
Anyway, on to my suggestion. I would recommend getting an IBM thinkpad. Yes, they are very pricey--especially when you compare them to other laptops that are cheaper with much better specs. I like the thinkpad because it's small and very sturdy! IBM is also quite reliable when it comes to customer support. If you don't plan on using your laptop for gaming or for photo manipulation, however, the lower specs found on an IBM thinkpad are fine. IBM thinkpads do come with higher specs, of course, but they are so much more expensive.
I've had a compaq laptop for most of my years in college--> this stupid laptop would ultimately push me over the edge! So, I then bought an Apple Powerbook. Compaq's reliability has gone down hill. And like the previous poster said, I'm sure HP will follow Compaq's path after the merger. Dell is still relatively better than most other brands. It's not as good or reliable as it once was, but it's not as bad as Compaq! Gateway has also gone down hill. Toshiba is also a nice brand, however, they're making their laptops bigger and bigger and BIGGER. I wonder why the weird trend? I would not recommend getting a Gateway at all! Very poor customer support--at least according to epinions.com and Cnet reviews. Sonys are sleek and affordable. However, I question this customer support and the reliability of their products.
That's just my 2 cents, I'm at work with nothing to do...so sorry for the long long long post.