Shaun of the Dead. It was better written, had some great character development, and I thought the plot was great.
Zzzzombieland was a boring film with unlikable/1-dimensional characters, dull plot and tired/unwitty 'jokes'. The only good one was Murray's regret. When I watched it the first time, tt seemed to me that it wanted to be some sort of romance movie in a zombie-infested world, but it completely failed. Shaun of the Dead handled relationships better.