My ideal tank would be one which is designed around active mitigation through constant self-buff rotations, similar to how the rift stalker in RIFT works.There stats would (appear) lower than other tanks at first and thus be some what squishy on the starting pull but once they get there buffs up and running they'd become an extremely effective damage-mitigation tank. There buffs and mitigation tools would be tied in with there hate tools to a point but not completely with the aim being to present choices to the player to make for there rotation, weather they need to refresh one of there buffs for example or go for the hate generation this round of abilities.

The skill cap would be higher for tanks who enjoy a good challenge since your rotation is going to be more then 1-2-3, the play style would be faster and funner since you'll always be responsible for your mitigation/survivability instead of just waiting to hit your big CD's for a burst of damage. But, that is just my ideal tank.