According to allmusic.com, 10,000 Maniacs did "These Days," on their Our Time in Eden album, though written by 10,000 Maniacs, not Jackson Browne. allmusic didn't have it quite right, though -- the song on Our Time in Eden is "These Are Days" -- not "These Days." But then 10,000 Maniacs does do a version of Browne's song on the Elektra 40th anniversary album. A little complicated. So I guess allmusic can be forgiven.
So I put on my I-tunes and listed the songs in alphabetical order and jumped into the various "These Days"es:
10,000 Maniacs (jackson browne)
Kinda boring, straightforward version. Nico's version is better. Tom Rush's version is better, too.
The Ropers (the ropers)
The Rentals (the rentals)
Nico (jackson browne)
Lloyd Cole and the Commotions (lloyd cole)
not bad, but no classic
Joy Divisionx3 (joy div)
The studio version seems like a throwaway. The live version on the official bootleg Les Bains Douches 18 December 1979 is pretty good, but there's a really kick-ass version on Paradiso, Amsterdam 11 January 1980.
Jesus and Mary Chain (jamc)
so-so, like the whole Stoned and Dethroned album