Depends what type of beer you like. If you like pale ales, then have another crack at one. if you like malty beer without too much hop have a go at a hell, or if you like bitter beer maybe try an ipa.
All the advice in this thread is good. Seems like you have 40-50l of beer to get through too...
Like the other posts above, I would use the same recipe as you have done, but try some hop additions. Boil some cascade and it cluster, then throw in some more after a few days into the fermenter.
Have fun!