I'd definitely choose from Thinkpad's (now Lenovo's) arsenal; They are robust, and yet sleek, excel in ergonomics and offer excellent durability and stability.
The knowledge base about these computers over the net is immense - you'll never get stuck without an answer.
The R series is Thinkpad's entry level laptops, they are bigger and slightly heavier, but offer great features for a great price.
The T series features the more expensive Thinkpads, as it's siblings excel in mobility without compromising on capabilities.
The X series are 12" notebooks and tablet-PCs, which master in mobility, while some of the devices, such as the CD/DVD player, are a part of the docking station, instead of the laptop itself, thus in order to compact the size and weight on-the-go.
If you are more of a student and less of a traveler, go with the R or the T if you can afford it. If you are more a traveler and less a student, and don't mind using a docking station with an external monitor go with the X. You can take these tiny notebooks anywhere. Again, a T will be perfect, combining mobility and performance.