I hate to say it, but Elvis Costello!
Now I don't hate the guy, infact part of the reason which led me to believe he's overrated is that I've been trying to get into his discography lately. On the way I loved alot of his songs, but hated alot more!
I find his early work from the 70's like My Aim is True and This Year's Model pretty decent, especially the latter but the problem is when we start heading up to 1979 and into the 80's.
He's touted as some Versatile and visionary Song-Writer, whose even on par with the likes of Dylan and Lennon. And 4 of his albums are even listed among the top 500 albums of all time by Rolling Stone. So obviously he's very acclaimed.
However I only think he matches up to guys like Dylan and Lennon only in his best days. And his best days are very few. Alot of his songs feel underarranged and even unfinished. With the exception of his first 2 albums, alot of his stuff has fluff, and lots of filler material.
I totally respect his reputation as a lyricist, very humorous and witty...he has to be up there with the likes of Ray Davies and Dylan in this department. It's too bad the wonderful lyrics is delivered with an oh so tedious voice, a cross between Buddy Holly and Elvis. But that rockabilly style of vocal delivery just doesn't work with his song-writing.
But even though he has few truly good songs, his best songs are actually GREAT songs. Better than the best that other song-writers have to offer. Songs like Oliver's Army, Allison, Veronica, Radio Radio, and Indoor Fireworks are truly inspiring. Addictive even. Makes you wonder why he can't write like that every-time. A thoughtful and blessed song-writer and singer, but his inconsistency puts him in a level (or 2) below the likes of Townshend, Lennon and Macca, Dylan, and Davies, where alot of people seem to place him. Wheras those artists in their prime wrote great material almost 95% of the time, Elvis Costello only about 45-50%...
My other pick would be Madonna, but maybe I haven't listened to enough of her. It seems to me, that alot of her impact is shrouded on her blatant controversies outside of her music...