An ancient thread, but a great one. Here are some more:
"The Spy Who Loved Me" (1977) - the motorcycle assassin plunging off a cliff (personal favourite)
"For Your Eyes One" (1981) - one motorcycle assassin smashes through a window and another tumbles down a snowy mountain
"Black Rain" (1989) - young gang member shot twice in the chest through his zipped up biker jacket
"Condorman" (1981) - lots of bad guys in full leathers killed in car and speedboat explosions. No closeups unfortunately.
"Death Wish"(1974) - the subway mugger. Also lots in "Death Wish 3" (1985) including a good one where a gang member is shot in the back of his sleeveless biker jacket.
"Friday the 13th Part 5" (1985) - two greaser boys in biker jackets killed, though unfortunately one takes his jacket off first.
"Les Insoumis" (2008) - French film where various faceless bad guys wear black bike leathers. There is a big shootout at the end with some good bits includung a guy getting pickaxed in the boot and through the back of his leathers.
"Brick" (2005) - boy in a biker jacket is executed with a headshot
"Blue Steel" (1989) - armed robber in a biker jacket shot and crashes through window
"Another 48 Hrs" (1990) - two outlaws in full leathers killed in final shootout
"Robocop" (1987) - bad guy in biker jacket dissolved by chemical waste and splattered by car
"What Have They Done To Your Daughters?" (1974) - Italian slasher film where the serial killer is a biker who gets shot off his bike in full leathers at the end.
"Watch Out, We're Mad" (1974) - Italian action comedy including a fight/chase with a gang of bad guys on bikes who are variously disposed off.