The dirty jokes are pretty terrible, but some of these are gold!
I was going to put my favourite but it's already in the OP (though I remember the punchline as "Do you know how to drive this thing?" - I think it was on the spine of a PC Gamer UK issue :P).
My other favourite corny joke is also one I learned from computer games - in this case the SimCity 2000 credits!
Three strings walk into a bar.
The first string shouts to the barman, "Oi! Gizza beer!". The barman points to a large sign that says "NO STRINGS ALLOWED", and croaks, "we don't serve your kind here," then kicks him out.
The second string thinks maybe it's worth being polite and says to the barman, "excuse me, kind sir, but could I trouble you for a beer?" The barman goes red with anger and shouts, "I SAID, WE DON'T SERVE STRINGS HERE!", takes one end of the string and tosses him outside.
The third string thinks for a minute, then goes to the restroom, loops himself around a couple of times and musses up his hair. He goes back to the bar and says, "Oi! Gizza beer!"
The barman squints at him and says, "aren't you a string?" String says with a smile, "no sir, I'm a frayed knot."
A frayed knot - afraid not - get it? :D