For me, if we're talking about the VII jedi saber forms, I'd say Makashi. It's quick and agile, just how I like it. If we're including other forms...Trakata is my answer. The concept is about igniting and de-igniting your saber. In other words, the main concept is about confusion, and that's why I love it.
Now for force powers, I think I'll split them too.
General:Force Repulse and Battle Meditation.
Repulse is like a giant Fus Ro Dah in a circle, with you at the centre. Why not? And battle meditation because it makes everything easier.
Light:Ugh. Mind trick and Force Stun.
Mind Trick because confusion, force stun because why not? :P
Dark:And here we have my favourite. Force Lightning and Force Crush. And Dark Transfer if I could have three, cos immortality :P
Force Lightning cos pwetty colours and Fore crush because power! :D