well looks like i will have to go with these....
In my personal estimation:
10. Rasengan - Alright...I put this here only because it has some versitility. It can disable or kill, damage people or objects. It does have some heavy drawbacks such as the fact it's REdiculously hard to learn, and it can often be difficult to hit your opponent with. While useful...it's very far from perfect.
9. Four Violet Flames Battle Encampment - Not only is it impossible to touch...it's seemingly impossible to breach...great for catching troublesome ninja. Only drawback; it takes 4 people.
8. Demonic Illusion: Hell Viewing Technique - This technique, while little used, has been enough to render people incapable of fighting (as seen when Oro used it against Sasuke and Sakura in the Forest of Death)
7. Cutting Whirlwind Technique - Temari's slicing tornado is both powerful and effective, not stopping for trees, rocks, people in its way.
6. Most Summoning Techniques - In trouble? Why not summon a giant slug/snake/frog/monkey/weasel/dog/gate?
5. Shadow Bind/Mimic - Useful in many ways. What other technique simultaneously renders multiple opponents immobile with minimal difficulty to the user?
4. Shadow Sewing - All the benefits of #5 plus more versitility.
3. Body Flicker Technique - Being able to move without your opponent seeing you? Always good.
2. Shadow Seal: Release - I'm surprised this hasn't been used more...not only can you find a use for all that extra chakra you don't use throughout the day, but you can unleash it and totally own all who oppose you...no one said it had to be used for Creation Genesis.
1. The Replacement Technique - Ok, this is number one because it's the single most useful technique in the whole series. How many times has someone evaded death simply because they replaced themselves? How many opponents have been bested because they were looking one way when they should have been looking another. This is, far and above, the single best jutsu out there.
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I thought fairly long and hard on these...I stayed away from techniques like Chidori and Shadow Clones because, while undoubtably effective, they are limited to the point where they aren't all that useful (for example, only a Sharingan user can effectively perform Chidori, or the fact that Shadow Clones divide your chakra). I also stayed away from Bloodlines...otherwise that's all the list would be.