Big Swirly Sky Thingie. Pointless MacGuffin to move the pace along. CGI Army for the Avengers (or whoever) to fight. Buncha snappy comebacks and one-liners.
That being said, there are a few highlights. The original Iron Man was pretty good, as was the first Captain America. The two Cap sequels were OK.
I've missed most of the ones over the past 2-3 years, WBill Jr just dragged me to "Avengers III, The Quest for More Money". I'm trying hard to miss "IV, We Need To Pay Robert Downey Jr.'s Salary Somehow".
I think you nailed it!
Call me a geek, but the attitude of your comment really does these movies and their fans a disservice. For example Captain America and Ironman are two characters that have had very clear character development arcs that reach their conclusion in this movie.
These arcs have something to say about the human condition, how people are motivated and how those motivations change their actions. Those stories are wrapped in dazzling superhero costumes, but like the Greek myths, the Geek myths are reflections on our humanity.