Super Saiyan-Jin Level 3icpg1252\uc1 \
This is once again, the next stage from a SSJ 2, or possibly the true final transformation of a super saiyan.  However, getting into this stage isn't easy, it requires MUCH MORE strength to transform from SSJ2 to SSJ 3.
Goku trained very hard to reach this stage and then had to experience extreme anger (sort of like the transformation to get to super saiyan) to get to this stage. The only difference between a SSJ 2 and SSJ 3 is that SSJ 3 has much longer hair and a much more vicious look. The eyebrows are gone and in the overall appearance they look very cool. Their muscles look pretty much the same as SSJ 2, but the hidden power is something that cannot be compared.
Advantage:
The SSJ 3 has much greater strength/speed/agility than super saiyan 2. This stage makes the Saiyan-Jin a true complete fighter.
Disadvantage:
Since a SSJ 3 is much more powerful, it uses up a lot more energy. A SSJ 3 fighter can fight for a while, but he gets tired very quickly. From Gokou's battle against Majin Buu, we know that resting will not build up or regain strength, it loses strength.
Interesting Facts:
Gokou is the only Saiyan-Jin to get to this stage. Brolly definately would have been able to reach this stage, but he died so it doesn't matter.
Gotenks is the first combined Saiyan-Jin to get to this stage.
Gokou asked Vegeta to replace him while fighting Majin Buu so he could gain some power back, however, Gokou was wrong. Vegeta was obviously much inferior than Majin Buu and got his ass kicked. Majin Buu left Vegeta half dead but Gokou still couldn't get his power back. Goku lost more power than he would have had if he kept fighting. He was forced to transform back to an ordinary Saiyan-Jin.
Who Can Reach This Form:
Goku, Gotenks, and Brolly if he were alive.