Aegis Boon II for about 17 seconds using a Vintage Kite Shield
Deflection for about 17 more seconds
Sentinel + whatever else is up or cross-classed while the above two are down.

That shield, plus a few nice abilities GLA gets, make damage mitigation crazy good on GLA. No class can match it (except a thm with a few broken abilities atm, but that's an entirely different arguement). To say that GLA is the worst class in the game is a bit of a silly statement. It may take us a bit longer to kill things solo, but if we are playing correctly, we won't die.

And HP at the moment isn't that big of a deal, especially considering the damage reduction we can do. With the way healing is at the moment, if you aren't killed in one shot, you have enough HP.