This list is but a small percentage of the available films in the genre, and are some of the funniest or most lighthearted zombie films you can find.
These were chosen as they are less gory than most, and are on the uplifting side. We also tried to choose more independent film (no classics in the form of Zombieland or Shaun of the Dead here, try something different!). Nonetheless, here’s our picks for a fun celebration in reference to the most well-known zombie appearance in history:

Cooties–A very no-consequences story of a distraught teacher coming back to his home town to find himself, when an outbreak (hilarious origin story here) traps him inside his school. Cooties has a really great cast of funny people with Elijah Wood and Rainn Wilson as the biggest stars, and is a great example of actors just having a good time.
Little Monsters–A small-time character piece for Lupita Nyongo that sets her as an elementary teacher protecting her students during a mini zombie outbreak. It doesn’t tread over any new genre conventions, but it is pleasantly weird and Nyongo and Josh Gad show they are a great fit in this genre.

Warm Bodies–Literally a Romeo and Juliet tale adapted from the book by Isaac Marion. One of Nick Hoult’s best films, it is a sweet and funny twist on the genre, with a rich new zombie mythology that sets itself apart in a great way.

Anna and the Apocalypse–A zombie musical from across the pond. You’ll know almost no actors by name, but this is a delightful experiment in bringing this genre mashup together. It is fun while it lasts, and as a musical, plot holes must simply be forgiven; it’s better that way.
Honorable Mentions
Slither–This is one of my favorite films, period. That said, it is comedy/horror, but BIG on gross body-horror (80’s throwback here), so it doesn’t quite fit the parameters for the list. Written and directed by James Gunn (Guardians of the Galaxy), this is a sci-fi/zombie genre mashup with top of the line comedic talent in Nathan Fillion and Elizabeth Banks.
Scout’s Guide to the Apocalypse–It’s a bit of a Superbad meets zombie genre film, a little more about the desires of teenage boys, but if that’s your prerogative, here’s a fun pick.
The Dead Don’t Die–This is a film for very few people. If you know who director Jim Jarmusch is and enjoy his films, then this extremely dry comedy should give you a good time. That said, it has a poor ending and is mostly pointless, despite seeing this quality cast play in the genre.