We were using the Bzz line from NE ropes on all Nacra's until recently. It is really nice, stays round in your hands and is light too. Only problem is that it wears out pretty fast and there isn't much warning before it breaks...
Had a few guys loose races this year because of it.

Conception from Yale is good too.

Keep an eye out for Alpha in the US soon. www.alpha-ropes.com