Oil or acrylic paint? (Bob Ross style painting)?

Well oil takes a very long time to dry, this can be an advantage or disadvantage as if you want to work on it for a prolonged period of time and blend some colors it may be better to use oil. The think that annoyed me most is that the Brushes are a pain to clean. You have to keep cleaning them in white spirit - it's annoying. Not much help i know but thats my experience :-)