Hmm, English Mastiffs.... lots of drool, don't live especially long, clumsy. Clumsy and huge. As a breed, they can be prone to hip dysplasia, gastric torsion, bone cancer, and kidney stones. Vet treatment is more expensive proportional to size.
I've known several EM's though, and they're all really amiable, affectionate, and playful (but lazy). Perhaps a little dumb... they seem to think they're lap dogs despite how enormous they are. I knew one that lived with five cats, and she got along with them no problem. Her name was 'Volga.'
Mastiffs aren't really my type - I dig German Shepherds. But they're nice dogs overall.