Well LEGO is a bigger brand of building toys,but lets can pair Lego to Mega Bloks’ used of their past lics:
SPONGEBOB SQUAREPANTS
LEGO:
The Sets are good like the 2006 Krusty Krab set as the one from the show and the one from 2009 as the Krusty Krab 2 from the first Spongebob Squarepants Movie,but some aren’t show based like Patrick’s Rock House.
The Minifigures have some are show based,but there some that are very aren’t to appearing in the show like Patrick is tall and Mr.Krabs’ Gray Tiny Claw Hands.
Mega Bloks:
The Sets are just for play features,but something like the boatmobles since Spongebob can’t ever drive.
The Minifigure have the likeness of the show with some minor characters,but they aren’t too hard for a Building Toy line.
TMNT
LEGO:
The sets are based on the current cartoon and the 2014 Movie with some are not based on any senses for the movie or TV Shows.
Minifigures are just the ones for the 2012 Cartoon and 2014 Movie,but I wished they could made a Bebop and Rocksteady Minifigures 
Mega Bloks:
The sets are based not only the 2012 series,but as well of the 1987 Cartoon with some Battle packs and the smaller kids toy line, too.
Minifigures are based on the 2012 and 1987 Cartoon series that actually pretty cool and at least Bebop and Rocksteady got some love.
The Mega Bloks Marvel sets are just plain horrible for my tastes,but Lego Marvel sets are way better.
Kre-O in the other hand is/was a nice break for LEGO with the little Kreons and yes I had some of sets and the blind packs.