spark plug problem

so about a year ago i noticed that my car would miss a spark when i floor it, like it would dog down, I eventually changed the spark plugs with Bosch's....I know Bosch sucks, didn't know that at the time, anyway. My car ran awsome for about 4 months then it started to do the same thing, this time I replaced the wires and put some AC delco plugs in it. My car ran perfect for about 2 months. Now i'm getting the same problem.
My question is I know everyone is going to tell me "get some Ngk's" and believe me then are my next ones i'm getting, but is it normal for them other 2 brand to only last that long, and will the NGK's last a long time?

AC Delcos are really good plugs. They should last way longer than that... I'm thinking your car might be running a wee bit rich and your just fouling them out. Run the NGK's and it might help a little bit...