Blueberry's (the Kurt Kinetic) is a fluid trainer. The advantage with fluid trainer is that it's quieter and it feels more road-like because you can "coast" to a stop. The disadvantages are that some people feel like it's too much resistance even on low settings, and obviously they're a lot more expensive. They can leak too.

It'll generally tell you if it's fluid or magnetic. They can look pretty similar in small pictures.