1. Godzilla (1998). It's an understatement to say this film is important to who I am as a person. Ever since I've seen this giant stalk the New York City streets, I've been hooked on giant monsters since. A personal favorite of mine to this day.
2. This is going to be very broad but I have to go with all the Godzilla roars. One of the most iconic sound effects in film histroy and I'd find it hard to find anything that tops it.