Airhawk R- I've had this Airhawk-R version for over 8 months now. It is specifically built for male riders with bikeseats that have a slope up toward the tank. (Warning: age appropriate discussion, following):

The inverted U-shape pattern of the leading edge alleviates the pressure on the "family jewels", thus there is no numbness normally associated with long distance riding. It fits the contours of the OEM seat very well.

I highly recommend this model, very comfortable. But your mates might tease you about it... until they are all begging for a butt break on your group rides and you're good to go another 100km...