Don't think liking HL2 is unpopular just because some people in this thread think otherwise.|
When HL1 came out, it was an absolute revelation. Consensus was that it completely overshadowed its rivals Unreal and Quake 2, and I agreed. Playing HL1 original or Black Mesa today, I must say, without the revolution counting anymore, Quake 2 is actually more fun to play (I always found Unreal lacking in gameplay).
When HL2 came out, it was a revelation again, and I agreed. Character animations and physics engine totally put its rival Doom 3 to shame. Playing them again today, Doom 3, although disappointing, is actually more fun to play.
Once you get past the revolutionariness of the HL series, it is pretty 8/10-ish stuff.