Weather Report - I like the debut (echoes of Soft Machine) and "Live In Tokyo" (echoes of electric Miles) but find most of the other stuff I've heard to be repellently cheesy and a good example of the shit fusion quickly turned to after innovations by Miles, Herbie etc.
De La Soul - I'd rank them among the best hip hop artists ever as well as one of the best groups of the 90's (yeah I know the debut was '89). I've loved the first 4 albums since high school ("Buhloone Mind State" is my favorite though "3 Feet High" is obviously essential) and only recently became acquainted with their later albums. Those later albums clearly aren't as good as the early stuff but I've been surprised by how enjoyable they are, especially considering my aversion to modern mainstream hip hop (and those later albums definitely have more of that sound). Testament to their greatness- even their lesser albums are better than most of what passes for hip hop these days.