I like Dell - I have one at home and also at work - they seem to be pretty robust components. There are always discounts available, so make sure you check out the discount sites before you buy!
I know of quite a few people who have started off looking at ones in shops, as they thought that the Dell ones were expensive, but actually when you cost up what you get - it worked out about the same as buying one from the supermarket as the level of what you get included is high.