LEGO doesn't work with SEGA. Nintendo works with K'Nex though, so SEGA's probably gonna have something for K'Nex more likely than LEGO. LEGO does more movie-based things than Video Games. One exception I can think of right now is the set of the Shadow-Fighter-thing-or-whatever for the Force Unleashed, and that's based off of Star Wars (a movie series) so that doesn't really count. To finish this answer, no there are no "official" Sonic Minifigs, but eBay tends to carry fan-made Minifigs of usually either decent or crappy quality.
lego.com
there is 16 Lego minifigures
Series 5 minifigures are already out!
sadly, no. but there is many customized justice league minifigures that you can find online.
they havent made a Lego minifigures series six
Lego Minifigures cost £2.00 each.
in target
metal sonic is not in sonic 3 only mecha sonic
You can find Sonic characters at Wikipedia and Google.
The best place to find minifigures or sets or even pieces of Lego outside of Lego itself is a website called BrickLink. Whether its new, used or hasn't been released yet, BrickLink is the place that all Lego sellers use as a marketplace and price point for selling Lego.
i do not no!!
no