I started out with fresh water tanks when I was a kid and found that keeping the tanks clean, planting, redecorating and just watching the way the fish behave was very relaxing. I went to SW for a few years once everything in the FW died. The variety in SW is astounding, but so is the pricing. Not too mention there is so much too keep track of that I just couldn't keep up. I gave my LFS all the fish I had and tore down the tank, cleaned it up and went back to FW.
So for me it would be the ease of FW, the selection of live plants, some of the colors of the fish, and just the fun of it.
