Right now, I'm really happy with my Primos Wench and Duck Commander "Ole' Raspy". I think the Duck Commander sounds the best, but I can work both of them really well.
I also have a Big River Magnum Acrylic Double Reed and a Big River Duck Buster Double Reed. The "Duck Buster" is a small wooden call, as opposed to the larger body of the Magnum. The "Duck Buster" is a mellow call, and I find it very easy to get feeding chatter out of it.
I also have an old Mallardtone (I'm not sure of the model) which is nice and mellow, and a Duck Commander Maximum Reacher which is very loud and raspy. I know the Maximum Reacher is a good call (my buddy's used one before), but I'm not used to it yet......so I'll reserve comment. You have to be pretty forceful on that call, otherwise it doesn't sound right.
I can't justify spending the money on many of the "boutique" calls that are out there, but I'm sure they are very good and worth trying if you can afford it. I'm just a hack out trying to shoot a few ducks, so I'll pass.
Browning BPS 10 Gauge 26" barrel
Browning Auto-5 Magnum Stalker 28" barrel