My current liking in a grip is the Serfas Connector. It is made by Velo for them in Taiwan and uses a ultrasonic fusing system to laminate onto a quilted form two types of rubber. The exterior of the hand grip area is soft and tacky with a quilted give. The form beaeath it which grips the handlebar is a much harder rubber. This lower, hard rubber layer extends to the end of the handlebar forming a thick, hard handlebar end covering.
The second choice is Oury MTB Rider grip. Many of the riders here at the store also feel the same. The diameter works well in the hand and the grip is thicker than many others in the areas of hand contact. The rubber material chosen to make the grip from is softer and more yielding than other grips. Oury has difficulties in distribution with only a few wholesalers selling them at all. We are frequently out of them in all colors.
The third choice would be the Yeti grip. It is not near as soft or as comfortable but it is substantial.
The fourth choice is the Answer Agressor which has most of the Oury features but is not as thick, or as soft or has as most surface contact area.