Not really the craziest I've ever made, but certainly one of my more creative ones can be found here.

The regex is:

/([^~])[^~]*([^~]).*~[^~]*([^~])[^~]*([^~])(?{local$z=$1 and local$y=$
+2 and local$x=$1 eq$3?$4:$1 eq$4?$3:($z=$2)&&($y=$1)&&$2 eq$3?$4:$2 e
+q$4?$3:0}).*~[^~]*((??{$y})[^~]*(??{$x})|(??{$x})[^~]*(??{$y}))(?{$x{
+join" - ",sort$x,$y,$z}++})(?!)/
[download]

Basically I used the regex engine to search through all the possible triangles and failed everytime I found one so I could continue searching for the rest.