Mario is quite ubiquitous these days. I never thought I'd see the day when I was tired of seeing him, but lately that's the feeling I'm getting. I'm not sure about games with other characters but Mario is definitely being used aggressively. But to be honest, Nintendo brings the goods and to me the quality of the franchises people claim are being milked are not going down. It would be nice if they introduced more new IPs though.
Playstation = The Beast from the East
Sony + Nintendo = WIN! PS3 + PSV + PS4 + Wii U + 3DS