1. ignoring speed instructions given many minutes and miles before any TOD, margins are tight these days. Min separation is 5nm and we might have you at 6nm, there is little room for error and a heading is pretty useless when that close.
2. issuing a descend NOW instruction, having it read back and then choosing to descend when you feel like it. The word 'NOW' is none standard RT but has become common practice as otherwise a descent instruction is replied with 'when ready'. I would have said WR if it was appropriate.
3. not listening on the freq when dialling in for the first time before transmitting.
4. not listening in general and when eventually found, denying you've ever been on the freq despite me issuing clearances you've complied with.
5. requesting descent/climb and when denied due traffic, stating you have it on TCAS...…………….erm!!
never a dull day in ATC, its a shame the days of chatter and a bit of banter are dying out due volumes of traffic.