I have been using LoveFilm for many months now without any problems. No faulty discs, no postal delays, it's great. The turnaround is as quick as possible, I get a disc Monday, send it back Tuesday, they send another on Wednesday and I receive it Thursday.
I went through a phase of not getting many at the top of my list, but recently, that's all I've been getting. You can also rent PSP games and UMD's, and they've just started doing downloads.
Hope this helps