Half-Life 1 is still an excellent game today, and is still one of the most revolutionary games of all time. Yeah, it looks ugly as hell compared to today's games, even with mods, but it's totally worth playing through just the same. The game gets better as it goes, so I definitely recommend finishing it. You won't regret it.

As for similar games to HL2, Gears of War and Halo are absolutely nothing like it, apart from the fact that you shoot dudes. In fact, I find that there aren't many games that are similar to it, but I would try Singularity and Metro 2033, as I definitely got Half-Life vibes playing those, and they are both very good games.

Thanks, I will try these two....besides Gears Of War:), Red Faction:Guerrilla, Section 8, Dead Space.

Ow, anybody like Call of Juarez?

also try portal and the upcoming portal 2. sort of half life 2's companion series.

Currently playing Quake 4.
Not as good as HL2, but still nice shooting game.

i am playing gears 3 ..i dont like how its third person shooter

Currently Biofuckinshock!
Great game!