In no particular order...
Blixa Bargeld (Einstürzende Neubauten, Nick Cave & The Bad Seeds)
Blixa hates guitar. He's said it in many interviews. His playing shows it. He approaches his playing from a uniquely Blixa angle. His stuff with the Bad Seeds is genius because he filled this in-between role of creating the number one thing I love in music... ATMOSPHERE. That is the key to Blixa's guitar work. I don't think he's particularly technically proficient, but his playing speaks volumes more than any flurry of notes or shredding can convey
Johnny Marr (The Smiths, Johnny Marr + The Healers)
Maybe my número uno pick if I had to make one. When Marr plays it's like he's said, you hear the whole record. His style of pseudo-rhythm and simultaneous lead is so marvelous. Growing up I developed a similar style on my own, though I will never compare my playing to the brilliance of Mr. Marr. His playing comes from a desire to make the guitar a fully realized instrument, not some under-utilized one trick pony. Love it. Love it.
Russ Cogdell/Brett Detar (Zao, "Where Blood And Fire Bring Rest" and split EP with Training For Utopia)
You can't split these two, it'd be like splitting up something that shouldn't be split. Lucy and Ricky, Laurel and Hardy, milk and cookies, peanut butter and jelly... wait. Peanut butter is pretty much good on its own. Right from the jar. Well, you can't split up Russ and Brett. It just wouldn't be right. Their playing was dark, atmospheric, catchy and dirty. Their tone was raunchy and real. If you are a fan of heavy music, and don't own "Blood and Fire"... Go and get it. It's so creepy. The entire genre of third rate copycats that the record spawned is beyond awful. Remember, ZAO perfected the dark art in 1997-8. All others have fallen so short. No one gives the Ramones flack for spawning crap pop punk bands of the 90s, so don't hate Zao for the chugga chugga bands of the 2000s.
Matt Fox (Shai Hulud)
Here is a man who makes his own code. Metal + Hardcore = Metalcore. Real metalcore. Not the terrible garbage they sell in malls and all-ages venues around the world, Matt Fox created a real form of fusion music. His style, background and attitude totally hardcore, but his chops- straight from metal. His tastes are diverse, and he champions those in the underground who never got a fair shake. He is a true innovator and a defender of the faith. Oh yeah, he's an amazing guitarist and songwriter as well!!
Steve Albini (Big Black, Rapeman, Shellac)
There are instantly recognizable guitar tones, and then there is Steve Albini. He's not on this list solely because of his killer tone (it's a big part) but also because he's another guitarist who deals in atmosphere and song rather than flash and flair. His playing is always unique yet still lands firmly in the punk rock ways though I've never heard another punk play like him. His playing is like Ron Asheton gone werewolf and possessed with the spirit of PiL and Gang of Four.
Davide Tiso (Ephel Duath)
Jason Martin (Starflyer 59)
Steve Von Till/Scott Kelly (Neurosis)
Niko Wenner (Oxbow)
Tom Wisniewski (MxPx)