MOTM

The original poster asked about a great sounding Flanger but didn't say 
anything about what he wanted it to do.  If he just wants it to swish up and 
down via a LFO, then many have given some suggestions, although forgetting to 
mention what some people think is the best sounding flanger the ADA.

But if he is like me and wants to wrap a sound up into an intense Tomita like 
flange that sounds like a jet taking off and hitting that satisfying 
through-zero climax, then he will be disappointed by them all.  For that, the 
Lexicon MPX 100 (and probably the MPX 500) has a preset with adjustable 
parameters, and it sounds great.  Or he will have to use two digital delays 
to also acheive a similar effect.

-Elhardt