Running the flag back to base in a game of Unreal Tournament CTF with a whole squad of the opposing team hot on your heels. Booyah!!!
Grim
I believe I’ve mentioned this before, but when I find what I know to be the cheapest gas around, boy! The rush is almost too much to bear. (The giant oil companies are not getting even an extra cent out of me.)
Also, a new but really enjoyable experience was when I waited for a suit to go on sale. I waited like three months, and when I went to look for it, it was there, in my size. My sister was with me and she laughed because she had never seen me so hyper. After I bought said beautiful silk suit, I said to my sister that I have had sex that wasn’t that enjoyable. Her reply, “We all have.” 
Along the lines of delphica’s copy paper mastery, I get a hardon when I’m looking for a particular page in a book - say a dictionary or a songbook - and I open the book TO THE EXACTLY CORRECT PAGE.
Ooh ooh! I just remembered another one. We have 2 wind-up chiming clocks. It gives me a special thrill when they chime the half or the hour at exactly the same time.
(Slinks off to the thread asking how folk accumulate high post counts.)
this is the holy grail of cheap thrills for me! i hate my supermarket…
…oh, and what Eternal said.
…and kicking the crap out of a wanna-be challenger in darts.
…oh! one more! BEER SALE!
Having my husband call me from the office and ask me how to spell something. [puffing chest out]I’m faster than the spell check. [/puffy]
Thought of one more:
Having someone “get” one of my obsure references in something I say. As in, " Well, I have to go now. Time for my **Flat Earth Society Meeting ** or even more vague references.
Makes me feel pretty damn good that there are few other like minded people out there like me.
Taking on a really tough fight in an IFGS game provides a huge thrill for absolutely no risk. Actually winning the fight is even better. The same goes for sneaking around successfully or doing something really clever (for an IFGS PC–we generally leave our brains at the check-in table) in game.
Last weekend I played my thief in a two hour game, sneaking around, picking locks, and scheming–all leading up to a really tough fight in which I pulled off a stunt that made everyone look at me like I had a “Bad Mother******” tattoo on my forehead.
The most severe risk involved was the chance that I would have to start the character over…and he would be more powerful if I did. I was still bouncing like a wind-up toy three hours later.
When I find myself with a lot of dimes and nickels, I like to go to a particular soda machine at work, insert 75 cents, pull the change return lever, and get 3 quarters back. Sweeeeeet.
When I click on a thread here at SDMB and it pops up instantaneously.
SWEETness.