How do you play bad players?

OK, so this guy is on an obvious flush draw in a $5 sit n go shorthanded at pokerroom.com, and I've got A,Q with a big, fat A on the board. He needs one more spade. He doesn't deserve the spade, so I make him pay for it. I bet the pot, about $275. He calls.
A junk card falls. He still doesn't deserve the spade, so I make him pay yet again. I bet $500.
Now, his odds aren't great here, 2 to 1 at the most, so he'll surely fold here, right?
Nope.
He calls.
And the third spade falls.
When he checks, I check, knowing I've been beaten, and he shows the King high spade. Oh, and he had K,3. Did I mention I raised the pot 4xs when I began the hand? I guess I didn't mention that.
Of course I"m on tilt, but I recover and try to make a move when the guys just to my left raises my blind AGAIN, so I re-raise him with 10,6.
On a medium stack, he calls with K,3.
Two threes flop, a 10 falls so I bet hard, and he calls.
End of game.
You know, I've found more and more that you have to either be bad and play ultra-conservative, or you have to play extremely well, better than me, I guess, to beat all these donkeys. The stragety of "just hang around until they knock each other out" works, except that it leaves you with a pretty short stack at the end, and that, my friends, not only sucks but just isn't much fun.
You really just have no idea what these people have. And while that is good for you, in a way, it also makes it pretty tough out there.
Maybe I should play some $1 sngs at pokerroom over Halloween weekend and let the party start!!!