RicOlie_2 said:
I still haven't seen the second Captain America or the second Thor movie--or, for that matter, any post-Avengers Marvel movies aside from Iron Man 3. Hopefully I'll get around to seeing them within the next couple years.
DEFINITELY watch Captain America 2 before you see Avengers: Age of Ultron.
I have no idea how relevant Thor 2 will be, but Cap 2 is an absolute necessity. Unless you don't mind having some huge Cap 2 events spoiled in Avengers 2.