Oxford Aviation has to be one of the best, if not the best in Europe and possibly the word (Bit biased though as that's where I'm training!). Also check out EFT (European Flight Training) in Jerez in Spain, they very good and Cabair in Cranfield here in the UK, also thought to be very good.
I did my phase 1 ground school way back at the beginning of last year between January and April on a full time classroom course at OAT and found it to be most helpful having no distractions and having other guys in the same position around me. However, I'm someone that hates 9 to 5 days so I didn't enjoy it that much and probably didn't get too much out of it.
I'm about to get all my phase 2 stuff out of the way by
distance learning. You certainly need to be strict with yourself when working at home, but as long as you stick to your plan you should be fine. I certainly prefer the freedom distance learning gives me. I can do four hours study a day, four hours flying and then do whatever I want for the rest of the time....pure bliss!