I typically get whichever cork or gel is cheapest. Gel is usually much thicker and cushy, and it doesn't cost much more. Some brands wrap easier than others. I like Easton and Planet Bike. Bike Ribbon is also good.

I just took off some Bike Ribbon cork that lasted about a year and a half and was still in good shape until I ripped it unwrapping it for a cable change. I replaced it with Forte gel tape. That seems OK, but it was a bit awkward getting the ends to fold into the bar.