HP's are nice, using one right now
In my personal opinion, I would say to stay away from Dell. I know some people who have had issues with Dell laptops, my friend had to get his whole motherboard replaced and he just got the thing a few months ago. However, I also know people who have had no problems with Dell. I haven't seen anyone have serious problems with HP though.
I also have an old Thinkpad, it's really well built and durable, if you need something tough, a ThinkPad may be a good choice.