Grab is one of the newer skills, it not only negates the mobility of agility teams but lets you get in more blocks and set up easier crowd pushes.
Guard is one of the most selected skills in the game and is useful on every team.
Juggernaut is one of the new skills in LRB5, while it can only be used by blitzing players it is still very useful.
Stand Firm is a very useful positioning skill and combos really well with a variety of skills. It can be used to really disrupt the opponents plans.
Thick Skull has changed in the way it works gaining a very small boost in performance at the same time. Now also a Strength skill who would select it?