Upnorth mentioned the F-111 and the Australian nickname, the "Pig". Such an inglorious label! I always thought that the name was in reference to the Vark being a gaz-guzzler, though. But the direct comparison to an actual hog makes sense as well.
The F-16 was mentioned, official and one or two unofficial names. Another rather over-used unofficial tag for the Falcon is the "Electric Jet".
The Iranian F-14's were known as "Ali-Cats". Also, USN Toms have been referred to as "Turkeys". Similarly, TBF/TBM Avengers were also known as "Turkeys". This is/was in reference to the look of each bird on approach. They both look like big-'ole turkeys, if you catch them at the right angle.
The F-4 has been subject to much re-naming, some of it unfair at times. My favorite is "Rhino".
The A-10 was mentioned, and the "Cross of Death" may very well have been a Soviet nickname for it. I dunno about that for sure, the only place I've seen that name in print was in a Clancy novel. I like just plain-'ole "Hog".
While we're talking about the Thunderbolt II, why not the first 'Bolt? The P-47 was referred to as the "Jug". This could be interpreted in two ways. The "semi-official" reason was that it was viewed as a juggernaut. Another is that the fuselage looked like a bottle of milk.
If I'm going on too long, tell me! (Excluding Berny! LOL) Also, sorry If I duplicate some of these already mentioned...
The F-8 (one of my fave fighters) was known as the "MiG-Master" as well as the "Mutha", though I prefer the former.
The B-1 is known as the "Bone".
The F-105 was known, as most of you might know, as the "Thud". Another was "The Triple Threat". First it would bomb you, then it would strafe you and, finally, it would fall on you.
The F-100 was called the "Hun".
The F-101 was also known as the "One-O-Wonder".
Fade to Black...