"Sure thing sensei, well suiton is the water nature of chakra. It is very versatile and can take many shapes and sizes depending on the skill of the user. To me it is the second best offensive element (next to Katon) and is also a VERY good defensive element (Waterstyle: Mizukagame no Jutsu).
Water vs the other elements give a variety of results actually;
Water vs Fire: As we all know, water is the natural remedy for fire and as a result is capable of dousing MOST katon techniques, of course there are some OP techs out there that need a mere ocean to douse. That being said, water should be the first counter thought of during a fight with a katon user.
Water vs Wind: Now this... I cannot imagine a suiton jutsu colliding with a fuuton jutsu. My guess is that wind would win. Say for example a waterdragon jutsu meets a cyclonic fuuton jutsu, I would think if the suiton tech isn't strong enough it would become engulfed in wind and becomes apart of that jutsu, like a typhoon or hurricane thingie. *Spark of ingenious* I bet thats how storm release was made! :O
Water vs Earth: Well, now we have the natural remedy for water, Doton. As seen in Naruto, Doton walls and encasings dominate the defense area. Especially against water attacks. Like the 3rd using that mud wall (earth variation) to block the 2ND's powerful water jutsu! Wasn't that something or what?
Water vs Lightning: Yep, we all know how this plays out...electrocution and paralysis. If you see a raiton jutsu, don't be stupid and use suiton (in most cases). Raiton is one of the most aggressive and versatile, against an ordinary water jutsu raiton would dominate, sending its killer intent electrons through the H2O molecules in mere milliseconds. Sad really."