We've been getting a lot of mail about HL 2 lately. I don't think that with any kind of malice, either. Fortunately, I'm a particularly patient type. Doom which was pure mayham. Quake which was the same with better graphics.
Original ideas makes all the diffrence.
After all, HL doesn't look like anything that came before it. HL will defently keep standing out for a few more years, as did Doom. From a multiplayer standpoint, this applies to a much lesser extent. Lots of mods are teamplay-based or at least support teamplay. If Half-Life had just been Doom with better graphics, I definitely wouldn't have liked it as much.