What do you think about Mario's 3D games?

What do you think about the main Mario 3D games?

I'm talking about:

• Super Mario 64
• Super Mario Sunshine
• Super Mario Galaxy
• Super Mario Galaxy 2
• Super Mario 3D Land
• Super Mario 3D World

I've heard and read a lot of opinions about the games. Some say "they're so repetitive, why they keep releasing Mario games?". I say each of them is unique and has a very different (similar in some ocassions) experience of gameplay to what others had. I have enjoyed each of those games, and completed all of them to the 100%. I'm basing my opinion on my own experience with them.

I was talking with this acquaintance of mine today. And he bashed out every new Mario game out there. "Nintendo should create new and unique IPs (intellectual properties) insted of releasing the same plumber every f***ing year". As obviously his opinion was biased since we don't get a new Mario game very year (talking about the main 3D games of course), I thought of asking here your opinions.

What do you think of Mario 3D games? Are they so repetitive and boring by now?