Guild Wars 2

against a HS thief all you need to do is cripple him and BAM his heart seeker wont hit you after you dodge away. I play a thief with pistol+dagger and double dagger (thinking about changing double dagger to short bow), condition build. Whenever I play against another thief who is heart seeker I evade as soon as I see him open, cripple them and then kill him. Against a pistol whip thief ill pop a break as soon as I get hit by infiltrators strike and then if they are classic glass cannon build you can kill them in 2 seconds, if they have more survivability it means they have lost a lot of their burst dps. AoE seems to be the key to playing against mesmers, if they play high stun/daze build though I have a lot of trouble usually.

Myself, rank 19 but I have played against rank 30+ so some people who have just been doing pvp are getting pretty high.