I own an Audio-Technica ATR-55 shotgun mic. I'm very happy with it. I picked it up open box from Best Buy for $25! It's generally $50ish.
I made my own furry blimp thing for it ( < $10 )with gutter screens, steel wire, costume fur, chopsticks and rubber bands. Works fabulously. I'm going to be fitting a properly threaded screw end onto the end of an extendable 12' painters extension ($14-home depot) as a boom. I'm currently using a mike stand I had laying around. It's quite heavy.
The blimp and boom work fabulously! We shot at a park on a windy day with 2 cameras. The onboard mic on one camera recorded nothing but wind...the other nothing but dialog!