Well the rudest thing a pilot told me yet was something like "I hope this works", while he was catching up on his preceding on the final. Never figured out an appropriate response, especially not while working.
What really stirs some anger in me is when I'm working on the director freq with 7 a/cs turning, reducing speed, intercepting locs, descending (blahblahblahblah all the time), and my fellow radars send me aircraft with a "contact director, callsign only", and the answer is something like "hello good afternoon radar, this is airline123, an A320 with info lima, descending fourthousand out of five, speed 220 on a radar heading of 160 and we are anytime ready for a visual approach"