People don't like to admit it put the biggest change in the NYC biking scene was the Guilliani administation's program of putting bike paths in a 'Greenway'. To the extent advocates influenced that they did a good job. I also think the 'Ghost riders' were a good idea in that it reminded riders (not motorists) of their mortality.
2000 Montague CX, I do not recommend it, but still ride it.
Strida 3, I recommend it for rides < 10mi wo steep hills.
2006 Rowbike 720 Sport, I recommend it as an exercise bike.
1996 Birdy, Recommend.
Wieleder CARiBIKE (folding), decent frame.