Yeah, there's a reason HotD2 is as seminal as it is. For a lot of people it's THE arcade shooter. Its quotes got quite popular in the internet age, too.
Also I think I heard that people consider it the black sheep of the "main" series, but I love HotD4. Sure, it's not exactly like 2/3 but it's still pretty darn fun and remains true to most of the series' conventions.
I still wanna play EX though, even though it seems pretty goofy.