Both Sagittarius and Aquarius love a busy and hectic life and love meeting people. These two are very likely to become great friends. New and progressive ideas and generally being in the centre of social action is something they both seek, so anything to do with clubs, theatres, outings and outdoor sports will attract these two.
But there are differences too. The Sagittarius is more enthusiastic and self-confident which makes them very warm and demonstrative whereas the Aquarius is a little more aloof.