The merging that annoys me most is when somebody stops and blocks a lane of moving traffic in order to merge into a congested lane leading to an exit.  I see this happen all the time when approaching the Queensborough Bridge exit westbound on Marine Way.  There's a predictably long queue of traffic in the right lane waiting to get onto the bridge, and some drivers scoot along the left lane and wait until the last possible moment to merge in.  This usually means they stop in the left lane, blocking everybody else who's trying to travel through AND butting into a queue of drivers who've been waiting their turn.  It's no zipper merge - it's just being selfish and entitled.