Although I am not a huge fan of avatars or 'Mii's it seems to add a sense of personality or a way to express oneself without having to make people read your about me section. Now Sony does have the Home Avatars, but they personally I find them to realistic and rigid. They look a lot like the mannequins you find at clothing stores. They seem to be missing the charm Mii's and Avatars have and maybe even Sackboy's have…?

I think from here on, Sony should totally use the Sackboy as more than just LittleBigPlanet (I believe, it has appeared in Hot Shots Golf??..)
Not only would the customizable Sackboy be a good avatar for PSN users, but it would also add personality to a lot of the Move games that are out currently, which in my opinion lack a certain level of personality.

Don't get me wrong, I think Sports Champions is great, i am not a huge fan of the stereotypical characters which you play as.

So what do you guys think? Should Sony use the Sackboy to compete with Nintendo's Mii and Microsoft's Avatars? And should they introduce them in games that are more than just LittleBigPlanet? 

Between Crash Bandicoot and Sackboy !!

Sackboy wins.

but I think someone or something else would fit the bill better than those two.

I would say Chuck Norris :P

No stupid avatars, please. I've always appreciated that Sony has some class and doesn't put bubblegum colors and silly balloon characters all over the UI.