Space magic is probably my favorite. To be able to effect the fundamental foundation of reality? To move instantly, create your own mini-realm, split your enemies apart at the most fundamental level, create impassable barriers, and just shatter base reality. Lots of fun applications.
Dark, though that's a bit cliche and thus has lost some of it's impact. Time can be really cool or just meh, it's easy to make it too overpowered or underpowered, but balanced right and in the hands of an intelligent user and it's really interesting.
Soul magic and Life magic, used well, can be really awesome too. Self augmentation, and complete alteration (extra limbs, natural armor and weaponry, parallel thought processing), the creation of monsters under your own control, turning your opponents' own bodies and minds against them. Not to mention the potential of linking your soul to multiple bodies so you can be in more than one place at a time, and have back ups in case one dies (you'd probably need to modify your soul to allow parallel processing first). Soul magic alone also allows stuff like sensing other's emotions and intent, reading their memories, transferring concepts directly to their mind, and possible extremely unethical soul alteration (read: slavery) for use by villains.
Force magic also has a lot of potential, despite the simplicity. A very raw and direct application of magic, can lead to cool and visceral action scenes.
Also, I'm upset at your element distribution! It's redundant what with water and ice, and rock and sand! And, 'wood' is highly specific, and leaves behind other bio-manipulation! 'Life' is the superior element! Or at the very least, 'Plant'! And then maybe have some separate element for Flesh/Bone/Blood. Better to just stick them together into Life though.