Can't decide... I want more shooters after Half Life anthology (though not HL2).
Trying to decide between Quake 2 and Doom 3 (+RoE), both of which i've played long ago. And CS:GO is an option as well, though i'm not sure how well i can focus on a MP game.
I've always liked Quake 2 but i'm not sure it will offer me more than one playthrough ultimately, and there's no "Quake 2 + mission packs" collection unless one counts the Quake Collection.
I paid 3.75€ for the Half Life anthology, and with only Opposing Force left, i am sure the games won't get another playthrough anytime soon, but i figure i've got a quite good deal ultimately. But i'm not sure this would be the case with Quake 2, especially without the mission packs (which i haven't played before).
The same value thing applies to Doom 3 really.
Both games are something i want to experience again as well.
I've always been the sort who prefers games i can play again and again and again but unfortunately such games are rare, at least in the shooter genre. Halo was something an exception for me for a long time.
MP games, when they're good, have this benefit of usually being replayable, and CS:GO most certainly ain't dead either...
(MP games also lack creepiness, Half Life was rather uncomfortable to play at times... It certainly had good atmosphere and feel even if it hadn't aged well otherwise.)
This is semi-question, semi-"trying to figure out my thoughts" post.
In case someone wonders, yes, they're old shooters. Unfortunately modern shooters often suffer from few issues: ADS which is an instant nope no matter what else the game offers, and/or being too demanding (laptop).
EDIT There's Unreal Gold to consider, i guess but i have no any prior experiences with single player Unreals and no emotional connection of any kind.