Personally, I suggest trying to go to an Apple store and trying out a Mac before you buy one. I hate both the keyboard and the touchpad on the new Macs, and you might find the same. Or you might not. But that'd be by biggest concern about Apple laptops -- the ergonomics are wanting in my case. Otherwise, they're great computers for many people (just not for me).
I like Thinkpads, because they are very reliable and well built. I voted for the T61, as it is around 6 pounds, but fully featured (unlike the 3 pound X61, which requires a dock to use the DVD drive). I have a T43 myself, and it has been excellent -- carbon fiber body to protect the insides better, dual wireless antennas, great keyboard, and the best touchpad I have ever used. In addition, like Apple, technical support is fantastic and the system is reliable.