If we're talking clutch on public servers as well then my biggest one was on NW_EU1 back in the day when it was still populated. Got 4 kills during the round and was last man standing 13v1. Got shot once but survived and killed most in melee (though I probably shot 1 or 2) thus ending the round 17-0. Unfortunately I didn't upload the screen back in the day and got a new PC so I don't have it anymore
Biggest clutch I've seen, hmm, probably Akame singlehandedly beating a whole regiment (maybe 10-12 people can't remember exactly) after we suicide charged them.
Also pretty fun to watch is this fight (not really a clutch though) by Jordan (a french dude, not sure if many people know him) back in the day against the 5pp. Start at 3 minutes.
Best players with the bayonet were probably Jackie, Akame, Harrier (if we were talking MM too I'd include ClaSh and Achilles but they rarely played NW). There are so many good players though, hard to make a top 10 out of that. I'll just throw some names together (not sorted or ranked) that could make up the top 10.
Riki, Axiom, Evan, Vikestad, Moskito, Robby, Yuriman, Flopz, Bessieres, Stephane (french), Mopin, Eddie, JHS, Xeon, Needsomemore, Graham, Melton, Whaleman, Vorlen, Herishey, Jammo, RebelliouS, Spartan, Sanitarium
There are/were tons of strong players but they wouldn't make it in the list imo, for different reason: Teamfights, Inconsitency, Variability, etc
Can't really talk about NA cause I don't know the scene that well, notable names for me would be Jackie, Zzetth, Sleek,Mathias