When I was younger, I played many, many games to completion, and that's all I did for many summers. As I grew older, my time has become more limited and as such, sometimes the breaks I must take between gaming sessions also happen to break my interest.
Command and Conquer (never Covert Ops, and when I tried recently it CTD'd me) as well as Tiberian Sun and Firestorm XP
Red Alert (no XPs), Red Alert 2 + Yuri's Revenge
Age of Empires and the Expansion
Starcraft and Brood War
Fallout, Fallout 2
Baldur's Gate, Baldur's Gate 2, Throne of Bhaal (I've played this through more than twenty times. I always come back to it, it's been kept alive thanks to a highly active modding community)
Neverwinter Nights - It took me four years to actually play the singleplayer campaigns... the OC sucked, Shadows of Undrentide I had to force myself to finish, but Hordes of the Underdark sucked me right in. I mostly, and still do play, on an online RP server for the last ten years.
X-Com I played when I was maybe 12. It was included for free on a PC Gamer Disc along with a bunch of other old games like Wing Commander for example. It wasn't part of the main feature or the autoplay disc, I had to dig to find it
It sucked away hours of my life, but being that young I gave up on the difficulty and started editing my bases and soldiers, but sparked a passion for strategy games.
I content mined the entire Mass Effect trilogy and Dragon Age (not the sequel, can't get into it) and all of the Halo's.
Nowadays I play more than one game at a time.
