We were in Seminyak. I didn't not have a good time, I just don't think the 16 hour flight justified the outcome. You could reach Cuba, Cancun, India, Thailand or one of the Caribbean islands with 6 hours to kill and I think you'd have better beaches, waves, food, culture, hotels, etc.
I think it gets such a big name because of it's proximity to Australia. The Aussies flock there because it's not Australia. They lap it up because it's different, of course in comparison to Austrialia it is, but if you're flying from the UK then I'd give it a miss and aim for something a bit closer......... (better?).
That said, I'd recommend Bali if you weren't travelling that far to get to it, and the scuba diving is excellent.