The majority of bulldogs are nice and intelligent, but there is controversy about breeding a dog where they are predisposed to many medical problems, the big one being difficulty breathing.
Any brachycephalic breed can be predisposed to brachycephalic syndrome, which can be costly to correct if needed.
They can be loud, snorting, gasping, flatulent and can also be very "drooly."
Other than that, they are a very desired breed and can be very fun and loveable.
This show is one of my favorites and is fun and informative:
http://animal.discovery.com/videos/dogs-101-english-bulldog.html
This show is in Japanese, but features two best friends, a bulldog and a chimpanzee who go on awesome adventures together.
http://www.youtube.com/watch?v=R7nNaUAWe44