Best to worst (best to worst in individual tiers as well):
Tier 1 (truly exceptional I would own them to the end of time if had infinite time to listen)
AKG K1000 (both 10000 serial #)
Audo Technica L3000
Grado HP-2 (x2, both pairs equal)
Tier 2 (Very good)
Sennheiser HD650
Grado HF-1
Tier 3 (Good)
Sennheiser HD580
AKG K340 (bass heavy) / Grado SR-225
AKG K701
Stax SR-404
Altec Lansing im716
AKG K340 (middle ground)
Tier 4 (usually excellent value)
Alessandro MS-1
Grado SR-60
AKG K81dj
Audio Technica A500 (really pretty bad)
Sennheiser HD590
Koss KSC75
Shure E2c
Koss SportaPro
red = no longer own
yeah the K340/SR-404 were kinda junk (SR-404 are actually probably the worst value headphone I've ever bought considering they sounded so bad and required an energizer)
Senn HD580 was borderline very good/good, I bumped it up to very good since it's only ~ $160 (and I do enjoy them quite a bit on even very amateur systems)
on K1000 vs L3000 it's very hard to rank one over the other. But purely based on technical merit the K1000 exceeds the L3000, but for listening time the L3000 gets most of my attention. This is because I don't have an amp for the K1000 at the moment and secondly I really love rock, jazz and blues on the L3000.
Hope that helps your research Nanoha, I think I've ranked every headphone I owned but I'm sure I forgot some