Journalists in the gaming industry said Nintendo was publishing too many Mario games after New Super Mario Bros. 2 (and then they begged for more 3D ones afterwards), and the series is now a yearly cash cow that doesn't improve much. What gives me the right to complain (since I'm a game journalist too) when I can offer proof that gaming journalists are stupid?
On paper...
Not including spinoffs like role-playing games and (original) sports games, the following have been the primary mario games for handheld and console since 2006:
Final Super Mario Bros. (DS, 2006)
Mega Man Galaxy (Wii, 2007)
The Wii version of New Super Mario Bros.
The Wii's 2010 Super Mario Galaxy 2
Nintendo 3DS's 2011 Super Mario 3D Land
Playing New Super Mario Bros. 2 on 3DS in 2012
The Wii U version of New Super Mario Bros.
At seven, and every one of them has offered unique experiences (with U aiming to stand out). Different types of Mario enthusiasts enjoy the 2D and 3D games.