I enjoy both games (FC and Hl2), I certainly enjoyed FC1 a lot more than all the non Crytek Far Cry games that I tried to play (FC instincts, 2 and 3);
but I've played and replayed both more than once and I think Hl2 holds better today, the open world in FC is not that open, there are several big maps (and quite like it, like on Crysis you can approach a "village" or something for a fight in different ways), but it still pretty linear, and it's no like HL2 doesn't have some big maps with stuff to explore here and there... I just think in terms of gameplay/campaign and even visuals (and sound) overall Hl2 holds better, sure FC1 have some great looking stuff, but at the same time the character models and animations are a lot worse, and the whole art style from Hl2 I think works better for me... also both games feel longer than they should, but I felt a little more tired and facing unbalanced fights on FC after 30% or half of the game, Hl2 is a lot more polished.
but those valve games are a really weird regarding vsync, I've played "opposing forces" recently, and just enabling vsync would give me a bad input lag, forcing fps_max 59 or something like 61, 63... seems to help... another alternative to remove tearing but not use the standard vsync is to run games on borderless windowed mode, but I think you need to add a launch command on steam for that on Source engine games, like -windowed -borderless or something