Actually the most powerfull things make the best jutsus. For mere destructive power Explosions work the best. They cover a large area, and don't require much on site chakra (it appeared that Diedra made them before hand). Pluss you could take out and entire ninja village with one big enough. THE ULTIMATE NASTY.
Second would probably be poison or gara's sand/shino's bugs. If you attack with an overwhelming amount of something from multiple different angles than you can pretty much kick some serious ass. Case in point -landscape of sand/ chakra eating bugs from all directions/ poison bombs and 1000 puppets w/ poison weapons- tend to do the trick.
Finally just plain physical superiority. Limit break moves like Lotus gates, 9 tails chakra, curse seal, curry pills. . . ect. make for a boost in strength that so far have been unrivaled (4 the most part) during the series.
Also the Zanku cutter was cool, but the character died off before I could make a proper analysis of it's usefullness+ Temari's version was better.
In the end thou I think it's more about how u use the jutsu insted of it's power. Shikamaru tango'd with 3 deadly chicks who all had much better jutsu then he did, but still did a pretty good job of runnin train.