yeah its a hard question to think about but...
On one hand you have salt, lots of beautiful fish, coral, and other amazing creatures. But that doesnt come free, saltwater tanks can be very expensive, hundreds of dollars( Not all but alot). But for the price you get beutiful colors and a huge variety of fish. Plus you have to deal with salinity witch can be a pain at times.
On the other you have freshwater, most have cheap prices (most NOT all), easy maintnance, and plants are good prices to, but you will be stuck with plain looking fish ( not all are plain but most are). Plus the variety isnt to good until you get into cichlids.
either way i like them both, if i had the cash i would definately set up a salt tank with a grouper, trigger, or butterfly. But i would not stop with freshwater because there are some cool fish you can get like angels, discus, or cichlids. Id have to say that the pro's and con's equal the out, it all depends on time, money, and intrest!
considering you asked it to be one sided this probably wasnt what you wanted, but it may help you figure out what you like better...