Birthday present for 6yo boy?

I'm pretty clueless, my kids are invited to that kid's party (he was in preschool with them last year and they're pretty good buddies) but I'm clueless what to get. Any idea? I'm thinking of getting one present, but maybe a bigger one, as both the kids are invited.
 
 

 

Lego's (Ninjago, Legend of Chima are really big right now), Nerf guns, anything Minecraft.

 

Kate hit it. Ninjago or Chima Lego. . .

 

Mine are all fascinated by the Chima speed racers right now.  They are not super expensive so you could get one from each kid.

 

My boys will be six next month and here's what they are in love with:
 
Lego's
Teenage Mutant Ninja Turtles
Power Rangers
Star Wars
 
They'd go crazy with anything in relation to any of those!

 

Don't you have an almost 6 year old boy? Just let him pick something.

But, Legos are huge here too. Anything superhero. Board games.

 

I do but he's still very much into the Disney Jr stuff, so probably a bad idea... plus I have Amazon gift cards to spend! Thanks, I'll look at legos!

 

Hot Wheels and car tracks..there are some neat ones out there right now  
Nerf Guns

 

Lego, Gears Gears Gears, Erector set, stomp rocket, science kits.