I like Weight of Determination, it's useful against fast opponents, like Kyuubi, CS Sasuke, 3rd Hokage and Yondaime. Very useful too if you use it against Gaara and Chouji. 2nd item I like is the Chakra Seal.
but you have to drop the paper bombs from the air or else they will blow up immediatly. i like the explosive seal (bomb seal, whatever), frog oil, and i guess the demon wind shuriken (i will use those for a while, i did the last mission like 60 something times and i have 99 of the demon wind shurikens).
Fav. weapon: Monkey King Enma's Staff transformation
Ninja Tool: exploding kunai
If ur doing the last mission to level up, try doing the scout 1 & 2 A-rank*mission. Its two battles + 80 points.* If u do a Ultimate jutsu in each u come out with at least 680 points total.*
My favorite tools would be seal tag, because u can take advantage of ur opponent and also u can easily to the infinate combo with ur character.. my second weapon would be poison bombs this would also give and advantage to decrease opponents life easier.