Well, not an easy question because of many reasons. I have been using Laptops since 1988 (first one was a REIN Electronic (Japan), extremely good portable). Some companies have a lot of experience in the field of portable PCs, like Toshiba, Compaq, etc.
Compaq and HP are almost the same, as Compaq is owned by HP. Toshiba always has been one of the best and one of the more expensive brands. Nowdays it is changing, Toshiba has the same price as others.
I have tried a number of brands (Toshiba, Compaq, HP, Fujitsu-Siemens, Acer) for a longer period of time and I am convinced that there is no "best choice", if you look at the same category of Notebooks. You can not settle even with one brand that you like for this or that reason as manufactures tend to change - for instance - the brand of the main parts in the same Notebook.
So, I would settle for a manufacture with a known experience in the field of Notebooks and that has knowledge in LCD monitor production (important, if you have a chance to compare).
My list of preferences: