I had a Lenovo last time and liked it. But this time there were a lot of complaints on the forums about certain features, especially the touchpad. And the "build it anyway you want" option was extremely diminished.
Dell let me do a good customisation but it did help that I got a quite decent academic discount on mine.
I'd always keep an eye on HP, Asus and Samsung - not every time do they make great stuff, but overall they tend to produce on average pretty decent kit. Narrow the model down with a bit of forum research - some models of almost any make can turn out to be lemony.