I'm making a Disney Infinity tier list to help people who want to buy the strongest characters. The list will be updated as more people post their input about characters.
Current tier list as of 12/27/14:
S tier
Wreck-it Ralph
A tier
Elsa
Violet
Vanellope
Mickey
Mrs. Incredible
B tier
Rapunzel
Anna
Mr. Incredible
Dash
Perry
Lone Ranger
Jack Skellington
C tier
Tonto
Davy Jones
Jack Sparrow
Barbossa
Syndrome
D tier
Buzz Lightyear
Phineas
Sulley
Randy
Mike
Jessie
Woody
Character Analysis
Wreck-it Ralph
His powerful button attack that pins enemies down, his strong but hard-to-use cherry bomb, and the fact that you can cancel his button into a trigger at any time puts him in S tier.
Vanellope
She can infinitely dodge, making her fast and hard-to-hit. Her shoulder charge is also unusually stronger than normal ones, and her cherry bomb hits hard.
Violet
Her invisibility combos can be avoided easily, but she has a five-hit combo in her button attack, and her ground pounds and uppercut combos can have great results.
Mickey
His button attack is strong and has great range, and his trigger projectile is great for getting in little damage from far away. His ground pound seems weaker than regular ones, however.
Mrs. Incredible
Her button attack combo and her elastic trigger attack work well, but her uppercut combo is less useful than other Incredibles.
Jack Skellington
He has a roar attack that can be comboed into a button hold, and his pumpkin bomb hits hard and can also be aimed. However, when the pumpkin bombs don't work on an opponent, he is forced to use his roars, which aren't very strong.
Anna
She has an excellent button hold that can be quickly comboed into a ground pound, and her trigger stuns but can set up for a basic combo. However, her finishing hit in her basic combo has lots of starting lag, which causes the opponent to be able to dodge out of it and begin attacking.
Mr. Incredible
He has a nearly unavoidable trigger attack that has great range and hits hard, but can be canceled out with a projectile. His normal attack combos are useful, but a little weak.
Lone Ranger
He has a great projectile that does little damage, but also stuns the opponent, leaving them open to shoulder charges and other follow-up combos.
Tonto
His projectile in his trigger is strong, but slow, and his shoulder charge is mediocre.
Jack Sparrow/Barbossa
Their button attacks are powerful, and can be used before a button hold attack for great results. Their trigger projectile only has one shot before a reload, but can hit hard.
Dash
His button combos, while weaker than usual ones, are quick and very useful, and his trigger is useful for getting a strong hit in and running away, but his trigger can be avoided with dodges.
Syndrome
His button combo is very weak, he is unusually slow, and his trigger can easily be jump canceled out of.
Sulley/Randy
Sulley's shoulder charge is powerful, and his roars are weak but useful in desperate conditions. Randy's shoulder charges are average, but he has the ability to turn faint, almost invisible. This can be used for sneak attacks.
Toy Story characters
Easily the worst out of these due to their mediocre shoulder charge, and extremely weak Pixar Balls. They can hit from far away, but they won't hit very hard.