If u have a LOT of budget, then a Alienware is the market leader.
If u dont have that kind of money, then depending on what you will need for a laptop. Gaming then probably Dell ( they have some laptops with 7800GTX quite impressive ). Asus is quite nice as well. You can have a Core Duo for about $1500
Take a look at Costco.com
I don't know why more people don't shop there.
Yes, the membership is $45 for a year, however the benefits are tremendous. You can return electronics within 6 months and they give you 100% of the purchase price back, no qusetions. Currently, I have 2 laptops that I purchased through Costco. I made the original purchase about 2 years ago and have been returning the laptops ever since. Every 6 months, I walk back in, give them my cleaned laptops and they give me cash. I then go pick up the newest model that they have and walk out. So, basically, you are getting the latest and greatest laptop they have for sale....all the time. In one case, I knocked the laptop off of my counter top and started to hear a noise from the harddrive ever since. So, one day, I opened the laptop to figure out what the problem was. I took the entire thing apart (normally, this would void every type of warranty or return policy). However after fixing the problem, I threw it back together and about 2 months later I returned it for a brand new one. In some cases, they took the laptop and turned it on to make sure it was still working, other than that .. it could be in terrible shape, but it doesn't matter, as long as it works they'll always take returns.
If you are thinking about gaming, go with a Sager. They also have the 7800 GTX for a lot less. They have the same internals as alienware becuase alienware, Sager and several others just buy them from Clevo and slap their name and small case details on before raising the price. Sagers are the exact same internally but are a lot less money and not as good looking.