Well, I'd argue that Iron Man 2, Thor, and Captain America didn't come off as TV Films, but I'd also say that they were suffering from one of the other issues that I mentioned above; whether it was that the films felt like they were under budgeted for the story that they were trying to tell (Thor and CA) or that it felt like Marvel was presenting a story where they could have gone in deeper with the source material but ultimately chose not too (Iron Man 2).
It's really the Avengers that I felt like gave off a TV Movie vibe in the sense of how scenes were executed at times with the types of shots and even camera/screen size used for it imho. I can't think of any TV Movies off the top of my head but I'm clearly not the only one that thought the same as I've read many feeling the same way as well.