Man,I love video games and I love to feel some stuff while playing like finishing a really hard game,finding a secret without a guide or just finishing any game in general.
But there's one thing I love the most.Some people here might know that I'm a RPG fanatic and while I prefer JRPGs I can't deny the Western ones like Elder Scrolls or the Bioware games.
For me,there's nothing like playing a mage and getting to the high levels and having all the best spells in the game.I just feel like this when I go up against most enemies,especially low level ones.

My favourite feeling when playing a game is cheating :D No, not entering cheat codes or anything like it. I mean finding something the makers of the game didn't notice or think about and exploiting it. A place in the boss' blind spot, a shortcut that should not exist, used a trap I was supposed to disarm earlier against the enemies instead, things like that. I think it's because figuring out thinks like that makes me feel like I actually outsmarted a game- found it's weaknes, thought outside the box, won in a way that wasn't prepared for me.

It felt fantastic when I beat Myst without any hints. It made me feel like such an "official" Puzzlemaster.

Successfully landing on Mun for the first time. Simply unforgettable

Accidentally murdering Luke with a backwards saber stab.
Well.. maybe not the 'best' moment, but it was very funny at the time.

Fiero. i.e. finally succeeding after trying for ages.

The sound of multiple "level ups" in Baldur's Gate.

Actually it happens more often in Icewind Dale, where you create the whole party, so there is a bigger chance of them leveling up together.

Then the title is well deserved! I liked Myst, but I admit in shame that at some point I needed to check the solutions because I didn't have the slightest idea of what to do next and wandered around for hours.
By the way, have you tried the DROD series? Beating it without hints made me feel like a real genius! Nothing better than cracking a puzzle that seemed nearly impossible at the beginning. The last levels of every game (or at least of the first three, the ones I've played) are fiendish.

Another thing I like is overwhelming the enemy in strategy games after starting from a disadvantaged position and slowly build my tech and army. Ah, those good times in Medieval 2 Total War when the Duchy of Milan became bigger than the Roman Empire through subterfuge, assassinations, menaces and corruption (the Popes have been my slaves for centuries) and the moment in Act of War where I destroyed enemy forces more than five times my size (I particularly liked this latter game, mostly because the AI is very aggressive and clever and there are no unit limits)!

Also, I absolutely love a perfect and clean hit in (pure) stealth games, my favourite genre.

Orgasm.

My friend gifted me Need For Speed Most Wanted on Origin. The client made me a bit angry even while installing itself - my computer just froze for a minute. But other than that all is fine.

Anyway, about the game... So I was racing yesterday one particular race not for a second or third time, but maybe 25th time already. I needed to win and unlock some parts for the car. But the feeling I got... This one time I started the race perfectly! From the very beginning I evaded some deadly corners, caught up with the leading drivers. And then this moment when I have to make a very sharp corner and not to fall from the cliff, and not to turn too much, and, and, and... And then while turning I gently crash into the leading driver, and side by side, we both made that sharp turn. Sparks flying from between us. I was squeezing my gamepad so hard, I thought i would break it.

The race had three laps. And all the way to the end I was driving, racing with the leading driver side by side. On every turn, on every touch my heart would pump stronger. Adrenaline built up for me, the race was so tense. And at the very very end I finished second, missed the first place just by a fraction of a second!

What a relief was when the race finished. And I was so pumped up with emotions that I grabbed my phone and called this friend to tell all about the race. Loved the moment.

Yeah, playing Postal does that to me too.

The only guilt I have about it is that I ironically beat the part with the rail transport system without knowing that I was supposed to find my way via sound. I just did it by trying every path and mapping out where I'd been. I hope to have a repeat of my success with Riven. I haven't, actually, but I plan to soon.

Immersion. When I'm totally sucked into a game world, that I forgot time exists. Not all games bring out that sort of level, and it depends on the genre, but the good ones do.

...what kind of game-
Wait, actually, nevermind, I DON'T want to know.

Stroker, I assume :o