Yamaha AV63+ (see petertyson.co.uk), Sony HT-SF1300 or Sony HT-DDGW800 all accept LPCM over HDMI and will therefore give you HD audio from the PS3. Obviously if you're budget can stretch, separates are the way to go. Sony 820, Yamaha 763 & Denon 1909 all under £300 at the minute, then add a speaker package such as the Q-Acoustic 1010i or similar.
As Andrew says though, what is your budget etc.?