I think David Bowie has shown amazing longevity in his career. It been 45 years and he's still recording music that's relevant. This year's The Next Day got quite a few critical raves. Bowie has had a few creative dry spells but he seems to always get back on track by bringing out good albums at regular intervals throughout his career.

@Gavin I think his original peak was Space Oddity ('69) to Scary Monsters ('80), disregarding the, ahem, not quite critical darlings of the '80s.

Frank Zappa.

Captain Beefheart. 1964 - 1982.

I think that I love the Captain more than anyone on Musicbanter, but Captain Beefheart definitely had a decline in quality with his two 1974 releases, Unconditionally Guaranteed and Bluejeans and Moonbeams. Granted, were they releases from another group I would most likely herald them as rather good, but for the Captain it was a hefty disappointment. I think his peaks went as such: 1967-1972 and 1976-1982. In short, I think he just released two bad albums while the rest were worthy of the acclaim that they held, save for the fact that the best of the best of Beef will forever be criminally underrated, imo.

Elvis Costello creative streak began 1977 (My Aim Is True) and is still making critically well received albums today. He had a few clunkers in the 90s but he's always managed to redeem himself.

Costello 4 and 5 star albums by the decade
(Based on AMC ratings)

1970s- 3 five star albums albums
1980s- 4 five star albums & 2 four star albums
1990s- 1 five star album & 1 four star album
2000s- 1 five star album & 4 four star albums
2010s- 1 five star album & 1 four star album

Bluejeans and Moonbeams is a very hit and miss for me. Bit more miss. At times there are some good blues riffs, twisted and nice tunes but it's a very watered down album that can get really tedious. The only thing I really appreciate is how it depicts Captain Beefheart going from obscure to melodic.

Unconditionally Guaranteed is ok. Same level as Bluejeans and Moonbeams. Didn't hold my interest.

Edit: God, I hate spelling those albums.

Wasn't the Captain more interested in his art by the Late 70's? That could have been part of why he went out of the music after a possible burn out from the industry. Still, Captain Beefhart had some standout albums, although if you include painting, he would be in the running!

The reason why I mentioned Zappa was that for all of his peaks and falls, as well as a troubling Early 80's period, he was always trying to create a world of his own plus creating a business for himself (Barking Pumpkin) and even debating the censorship hounds in a very intelligent manner. True, there was a lot of ego as well (of course there would, you have to have it!), but it fitted in with what he was doing through the years.

I love it. Everyone else should too.

A nowadays band that's renewed my enthusiasm: The Aristocrats. 2 albums have come out and they're both out of this world. I'm hopeful that they'll keep on like this for a long time.