I have to disagree for its time HL2 was a groundbreaking title. And all of those "standard" weapons came about because of games like HL and HL2 (but not just them).
The HL series has a great storyline, it just isn't shoved down your throat like in some games. You are left to discover it, you have to listen to people, look around like you would have to in real life. You don't get to see what Breen is saying to the Combine Advisors, you don't get to see what is happening hundreds of miles away, you see exactly what Gordon sees, and I loved that about it.
Episode 2 really improved on the AI an some of the other problems you stated. I thought, gameplay wise, it was as good if not better than the original HL2.