Without going and reading all of the pages of responses, I will say what most on the 1st page said.....stick it out. There is only one thing worse than a training contract and that is somebody who signs one and then doesn't honor their commitment or at least pay it off. Now I don't know how old you are or how long you have been flying for a living, but the flying industry is a very small world. You might think by leaving now that you are going to get yourself ahead faster. In the end this might backfire on you and you might find yourself stuck somewhere from being labeled a "Job Hopper", a "Type and Runner", or just someone one who's word means nothing. Now if your working conditions have changed and you find that you are being pressured to fly unairworthy aircraft or to break other regulations, well that is a completely different story. From the tone of your question, I don't get the feeling that is the case.
Here is how these things work:
2 year contract=Operator you probably don't want to work at for 2 years. Also, more than likely equals below industry standard pay.
1 year contract=Operator you might want to work for, but they are on a tight budget and the pay is probably slightly below standard.
If either of these contracts are non-prorated, then it is about a 1/2 step further down the pole.
No contract=Operator who treats their pilots well and an operation you want to stay with for many years. Pay is usually above industry standard.