Darksiders.  I rarely take a chance on an untrusted source these days, because you're more likely to be burnt than otherwise, however I was pleasently surprised.  I found the combat more fun than the original God of War, while still just as repetative, and the addition of decent puzzles worked well.  The Art style and characters made the game feel like its own.  It gets canned a bit as being a GoW clone, but frankly it's got more personality and more brains.

The impulse purchases that I have been the most happy with would have to be a tie. Corncob 3D and Simcity 2000. For those of you who missed Corncob 3D, it was truly strange flight sim that had you piloting bi-planes in a fight against invading aliens. It had solid and smooth moving graphics for 1992 game allowing you to fly in all three dimentions, but was devilishly hard. I don't know if it was sold in stores, I mail-ordered it after trying the shareware.

Jagged Alliance:Deadly Games.

It looked awesome, plus a new character was a crazy-psycho disgrunted Postal Worker.  it was the second game I ever bought for the PC (the first being Lords of the Ring: Part 1..it was bad) and I played for months, if nto years.  I still recall a few parts of it with my brother (we both played the game and we kinda loved the whole Jagged Alliance Serie)

But recently?...hard to say really...everything is the same, just with a diffrent coat of paint.

Morrowind for me.

Never heard of the Elder Scrolls but I picked it up because the screen shots looked epic. Spent many hours tramping around in that game never to complete it.

Nox!

I would have to say it was ARENA. From the elder scroll storyline.

I was always a D&D lover and that game came close.

After that I just got to old and never really had time to have fun playing any game for a long time just like when i was a kid.  Hell I've been playing zelda for the WII for the past 2 years and it's still not finished. Having three kids is a real killer

Sins of a Solar Empire was probably the last game I bought in store with very little prior knowledge that didn't end in disappointment.

I've been burned enough times throughout the years that I very rarely jump into a purchase without at least some advance knowledge of what the community and user reviewers (professional reviews are mostly a load of bribed crap these days) generally thought of the game.  Not to mention digital downloads mean there's even less excuse for not researching a game before buying it.

I saw Sins and bought it, with no prior knowledge.  It's still my favorite game.  (For console, Mass Effect)

-Twilight Storm

Heroes of Might and Magic IV. I missed it out after III as I heard bad things about it and skipped to V. Saw it cheap and bought it and I have to say the people who criticised it need a good talking to. It has far more RPG and strategic options than any of the others but the fanboy purists drowned out the more objective of us with their tremulous, whiney voices.

Baldur's Gate series: a friend had been telling me about it for months.  I finally bought the first game, loved it, and then bought the second came (BG2).  Loved it even more. 

Kings Bounty The Legend - its a super game!!

I haven't played it that much yet (it was released less than a week ago), but Lead & Gold would fit. I saw a couple people on forums talking about buying Lead and Gold and thought "WTF? I understand gold, but why the hell are they buying lead as well?". A bit later I finally realized what they had meant saw screenshots, noticed its price and voila! new item on my CC bill. Pity I haven't had much time to explore it, too busy with classes yet but what little I've played of it has been great

Here on Impulse however it'd be Scavenger, a few months ago. It's kind of like Moon Lander made into a shmup, and believe it or not it's awesome first time I played it I couldn't stop until I was at lvl 40, and even then only to buy the studio's other two games ArkLight (Arkanoid made into a shmup!) and DarkSide (Asteroids made into... even more of a shmup!) before resuming my obsession.

I'll have to go with GalCiv2 also. I had picked it up and put it back down on a couple of occasions(instead buying CivIV and SM's Pirates those times). Finally I held on to it when I picked it up and that was the start of 2+ years of playing almost daily. I still keep it at the ready in case the mood strikes.