I think someone else should answer that question. Although I'm a fan of Fantasy (a FAN-tasy, if you will), and have been reading the genre almost exclusively for most of the last two years, I don't really have the 'experience' that some of the others here do.
The only Fantasy I've read is Robert Jordan, Tolkien, J.K. Rowling, Stephen King, David Anthony Durham, China Mieville (if his books can truly be classified as Fantasy) and Brandon Sanderson. Of those, I can't say anyone is remotely similar to Abercrombie. They're all very good in their own -- but quite different -- way, though. Except Durham, whose Acacia I found underwhelming, though it had enough promise that I would want to see where the rest of the series goes.
One author who I've heard Abercrombie being compared to (but haven't yet read his books) is none other than George R. R. Martin, at least in terms of 'grittiness' and good characterisation. Not sure if GRRM has the same sense of humour, though.