Full coverage fenders, a bunch of companies make them in either metal or plastic... many good reviews in this forum.

I like to wear a rain cape in the rain and I have an extra long mudflap on the front fender and that keeps me much more comfortable than rain suits did. Personally I wouldn't ride a fender-less bike in the rain. I don't mind riding slower in the rain but the rain capes can take some getting used to if it's windy. The cycling specific rain capes are much nicer in this regard but I just suffer the indignity of a 10$ rain poncho and I stay pretty dry. If you ride flat pedals I also use galoshes or overshoes since I hate wet feet. I always wear wool dress socks (best socks ever) so I don't find overheating.