Hi, I want to contribute to this thread, since I root many devices almost every day.
in general, there are couple of softwares that I use, and try one by one if first fails.
1.
TOWELROOT
- works on newer Samsung models, good tool by GeoHot, uses some latest exploits, can be tried on other brands too
2.
KingoROOT
- works on many different brands, fully automated, requires cable connection and enabled USB Debugging
3.
VROOT
- similar to KingoRoot, but installs some Chinese apps, and Chinese SuperUser app
4.
MTKDroidTools 2.5.3
- very usefull app for Rooting, and many other things, especially made for MTK devices
notes:
- for some specific Samsung firmwares, and devices, custom recoveries must be flashed and through them SUperUser be installed
- for some specific MTK devices, similar as above procedure must be done, via MTKDorid tools
feel free to edit my post, and add some info.
b.r
Alex