Users who own this game also own:

Portal
Portal
Half-Life 2
Half-Life 2
Portal 2
Portal 2
Left 4 Dead 2
Left 4 Dead 2
Deus Ex
Deus Ex

Users who love this game also love:

BioShock
BioShock
Half-Life
Half-Life
Doom II
Doom II
S.T.A.L.K.E.R.: Shadow of Chernobyl
S.T.A.L.K.E.R.: Shadow of Chernobyl
Batman: Arkham Asylum
Batman: Arkham Asylum