Doesn't everyone? I like "a face like a bulldog licking [slang word for urine that rhymes with hiss] off a nettle" myself. Although "a face like a blind cobblers thumb" is good too.

A face that would stop a clock or a face only a mother could love are marginally more polite versions.

(And its only a matter of time before this thread inevitably spins off the Kingdom of Peace and Love rules, surely?)