Originality is a precious commodity, but if you don't mind your old fashioned fantasy tropes with new life breathed into them, then there are three British writers I'd recommend - two are just emerging, one has been around a while but is only now finding his voice. Joe Abercrombie and his First Law series, James Barclay and his Raven cycle and Stan Nicholls and his Orcs series. All of them write traditional action based fantasy novels, but add an earthiness and snappy dialogue that's so often missing in other High fantasy. Jane Lindskold is a touch more traditional than the three British writers I've mentioned, but her characters are engaging, her novels are tightly plotted and well paced and she has good ear for entertaining sarcasm, particularly in the Firekeeper series.
If you want something in a vaguely
similar vein to the great Mr P., then there's not a great deal out there beyond the already mentioned Jasper Fforde and Robert Rankin, as well as Tom Holt and Robert Aspirin. Maybe try The Fallible Fiend by L. Sprague de Camp? that's really good fun.
I also hear good things about Kim Newman, but I haven't had a chance to read his work yet.
If you don't mind a darker and more horror tinged edge to go along with some witty dialogue and fast paced action in a real world setting, then maybe give Mark Chadbourn or Christopher Fowler a try. Both of them are very good indeed, but don't rely on either of them for a happy ending.