Okay. Going my pictures of when I saved them. Superwiki and ONTD_spnparty pics, I came up with these.

#07 I'm pretty sure it was taken after Kim had dumped all that water on the boys [see gag reel] and that was from Season 2 No Exit

#30 http://bauergriffinonline.com/2010/01/padalecki-appears-pumped-up.php Season 5 either episode 16 or 17.

#33 BTS of episode Metamorphasis, Season 4 I'm pretty sure I remember the third guy was the one that played the Rugaru.

#49 BTS Good God Y'all season 5 [picture probably from andreas_ri since he has that one and others]

#77 BTS of I'm pretty sure Route 666, season 1

#147 BTS of Hook Man [picture probably from andreas_ri since he has that one and others]

#157 I don't know what episode it was for other than *probably* season 6 (unless it was a 'photoshoot' because Andreas has another one where kinda like this but the guys are leaning on the Impala) but I know I first saw it from andreas_ri. I'd have to look at episodes to see if Sam is wearing that colored shirt.
http://repro-images.net/08/hell/HLAS11-0003.jpg
http://repro-images.net/08/hell/HLAS11-0022.jpg

#170 BTS/on-set picture from Season 6, episode 17 My Heart Will Go On http://www.flickr.com/photos/susangittins/5431684482/

#178 BTS/on-set picture from Season 6 episode 13 Unforgiven http://ontd-spnparty.livejournal.com/348341.html#cutid1

Hope this helps a bit. :D