It depends on what your campus is like, but the big thing now is having the "male beauty pageant". Sometimes it's called Deepher Dude...other chapters call it "Big Man On Campus", but it's always a good money maker if you have a good greek system. Another good one is a date auction. This worked out really well at one chapter.
On a smaller scale, you can do things like car washes, vacuum a thons, working at theme parks or big sporting events for pro teams. These all have worked in raising funds for philanthropy.
For community service, if your town has a park, work with the town and the other Greeks to do a park beautification day, where you rake leaves, plant flowers, etc. Get the town to provide the flowers and equipment, and you'll do the work. It's a good way to build relations with the town. You can do a campus beautification process as well, where each greek organization might get a small plot on campus to keep neat or plant flowers and such.
Good luck