I love 'Watchmen'. One of my favourite films (I'm a fan boy). Less accessible to the public but more faithful the the graphic novel.
Old guard versus new blood. I like 'Watchmen' more because it's more sophisticated, had a rational plot and focuses on the characters (a realist's film) whereas 'The Avengers' which I extremely liked catered to a mass audience who thrive on popcorn entertainment (but lifted the mark for Marvel movies because the characters were
real and developed). Nothing special. I can see why these two films are being compared. 'Watchmen' is the superior film, in my opinion.