I have heard a ton of good ones, some on here.
Last night I was playing a match, and I am just coming back from a long layoff, and was playing well below the norm. Anyway, I did manage one paticular great shot. I had my cue almost frozen to the rail , and only had a bank on the four. I play the bank ( not really even expecting to pocket it) the bank falls and the cueball goes two rails and gradually rolls to perfect position between the five and six which are literally about two and a half balls apart and on the rail. The cue ball stops in place without even touching the rail. I just looked at my opponent and said " I am taking pre orders on my video, it'll be out next month". I know someone else said pretty much the same thing earlier, I just wanted to brag about my shot that was still fresh in my mind!
When I slop in a really obcene shot, I will say " I'll teach you that shot, as soon as I learn it" Or " And now for my next trick" or "Where's an ESPN camera when ya need it!"
If I leave someone in a tough spot I'll say " Now your out, OUT OF OPTIONS!".
I still remember one night many years ago, I was playing a fairly high ( for us at the time) money game with a player from another room. I was representing our pool room and he was there with a group from his. There were a lot of railbirds standing by, and a lot of people interested in the outcome. It was at the end of a pretty close set, and he left me real tough on the seven. The seven was sitting near the headspot and the cueball was at the far end of the table, with the nine directly in line, blocking my path to it. I knew I was probably about to give my opponent a ball in hand three ball runout. I proclaimed loud enough for everyone to hear " Cool, my favorite shot!". I got down to give it my best effort anyway. I kicked that ball in dead center of the pocket, the cueball rolls into a perfectposition on the correct side of the eight. The place went crazy. Although I was totally being sarcastic, and really just trying to get a hit on the seven, I spoke that line with enough confidence that a lot of people who did not know me well enough actually questioned if I was serious! I still stand by the fact that I make that shot 9 out of 10 times.
