Here's a few links to the better brand seats for bikes in no particular order.
Saddlemen
http://www.saddlemen.com/
Mustang
http://www.mustangseats.com/
Lepera
http://www.lepera.com/
Danny Gray
http://www.dannygray.com/
Corbin
http://www.corbin.com/
Seat alterations
http://www.meancitycycles.com/
Butt Buffer
http://www.buttbuffer.com/
Gel Pads
http://www.knoplace.com/Gel_Pad_Installation.html
Russell
http://www.day-long.com/
C&C Seats
http://www.ccseats.com/
Extreme Seats
http://www.extrememotorcycleseats.com/
Bar Enterprises
http://www.harleyseats.com/Bar_Enterprises_Welcomes_You.htm
Saddlemen
http://www.saddlemen.com/
Mustang
http://www.mustangseats.com/
Lepera
http://www.lepera.com/
Danny Gray
http://www.dannygray.com/
Corbin
http://www.corbin.com/
Seat alterations
http://www.meancitycycles.com/
Butt Buffer
http://www.buttbuffer.com/
Gel Pads
http://www.knoplace.com/Gel_Pad_Installation.html
Russell
http://www.day-long.com/
C&C Seats
http://www.ccseats.com/
Extreme Seats
http://www.extrememotorcycleseats.com/
Bar Enterprises
http://www.harleyseats.com/Bar_Enterprises_Welcomes_You.htm