Interesting question, but not one I can answer with just one costume.
My favorite *movie* costume was Jason. I based it on Jason from
F13 Part 6. Tan work pants, an olive drab army shirt, leather work gloves, and legitimately worn hiking boots (after five years of use and nary a polish, they had reason to look worn!). An army-style pistol belt, machete scabbard, and plastic machete completed the ensemble.
The mask was
Dead Meat from Death Studios, with one of the standard plastic hockey masks available at that time, a tad modified to make it look more like Jason's.
You tell me how it worked out....
The next one is kinda semi-based on a movie -- specifically, Roger Corman's
Masque of the Red Death -- but since I look nothing like Vincent Price, I did some modifying again.
The robe is actually four pieces: the robe, a separate hood, a band (I don't know what else to call it) that wraps around the throat of the mask and fastens in back with Velcro, and another piece (I think some people call it a tabard) shaped like a V, front and black, that fits over the entire thing and fastens with Velcro on one shoulder. There's also a nylon rope belt dyed red and red Spandex gloves. I used Naturalizer driving gloves and removed the leather pieces with a seam ripper. Skin-tight fit, which was what I was after.
The mask was from Death Studios again --
Corpus Delicti. DS used to do repaints of theirs masks, provided it used colors they already had. I had them repaint
Corpus so it looked freshly dead, with lots of blood in the open sores.
The result:
Close-up of the face:
Gotta do some scanning before I continue this....