Hmmmm. I could tell you -how to beat the ones that try to beat the nasty sbs- ^^..
but so far, the biggest enemy of the sb is a team. That can be 2 to 8 players, atleast ppl who stick together. Killing 2 people is harder, and surviving an attack against them too (tho, if they got no templar it doesn't mean the sb automaticly lost.. then it's timing (stuns,St etc) and skills to beat him, else his PS+CB/step away and CB/BS step away tactic will kill you anyway..).
Another way to beat sbs is the reaver. BA (bone armor) lvl 12, sprint 12 and telepush and/or telehold at any lvl is kinda a must-have.Gash and BB means a bleeding sb, also good to have. FA/Flurry can be good in some cases, but if you don't know how to handle CB/veil its bether to keep gash mixed with FA or WW for melee, and BA/sprint for dmging them and speed, and TP/TH, atleast one of them, but against sb its bether to have both of them.
My favourite build for both, random playing and sbs in one is BA sprint gash FA lvl 12 and tp/hold 1.. Sprint, telepush and gash, then sprint back and forward and hold (to avoid getting hitted right after TP/gash..) .. and then gash or FA.. if FA would kill him FA, if not, gash him.. because if he run away he has to stop or he dies, if he stops you go to him and kill him, if he moves then he die anyway.. if he attacks, your attack+BA dmg will kill him anyway, and you wont die since you didn't take any/much dmg with those simple steps ^^
Templar: Bash and Blessed strike, Cure and heal.. thats it. First hit = normal attack to avoid Cb, and bash right after. 1hit and Blessed strike.. normaly he's death or low health.. but since you can curea nd heal, and you avoit his CB+BS combo, its no problem.. to let him run away with less then 15% of his life, dont follow him its just a waste of time.
Prowler: You don't even need to kill him.. if you play prowler, play supporting prowler, else you dont even have to play prowler because they are just as annoying as the sb you want to kill. So.. you have bird lvl 1, scout lvl 12, entangle lvl 12 and MS lvl 1-12.. then you can choose between shriek,AS and so on.. if you MS/entangle and scout away (shriek if you got), he normally can't follow you and you go on supporting your team, get relics shriek enemys entangle relic carrier/enemy templar etc..
as Seeker yu gotta stay with your team(mate), or you'll loose atleast half of your life.. usefull skills can be Bullrush , Fury, BC, and KB to stop him and maybe run away to BR him again when you are in fury, and AB to deal more dmg (that might help if your BC lvl 12 or high skilled BC hits him, else you just deal dmg and die).. and taunt. MJ lvl 12 can be used too, frag mines are more or less crap if you are no miner/bomber/taunt seeker..
A way if a sb attacks you could be: Fury on,hit (and turn 180° if CB is on), BC and then KB, run back and BR as fast as you can if its not on CD, and kill him with an attack while hes stunned.. or just use your skills wisely and avoid his poisons and CB/BS as good as you can.
as witch it depends on your skills, since there are just a few that can really kill a sb when it attacks you.. NW, Soul trap (when he staps away), CM+MV can be useful... and CE to see him when he attacks you, then you can act right..
And as I said, ignore him (as charakter, so that he thinks you didnt recognized him or don't care, but as person you take care and act in the right moment and blow his ass.. just watch out and listen to the sound of his step/meld and stun with a non-melee attack first(TP,TH,BR,MS,MV,NW...), if you dont have such an attack.. attack first to avoid CB and then use a stun attack(bash,BC,sprint+FA,BS..).. its always like that.) and stay with your teammate if you can't handle "skilled" sbs ^^ since its a teambased game ..

and practise, practise, practise ...
good luck!^^
if you can host server i could practise with you as a sb, got 8 weeks holidays I think I'll find some time if u tell me before, since servers are most of the time empty, I'd like to play some DS :/ )