Thousands of tutorials to learn from
I’ll vote for Solid Works – easy to learn, very popular, accurate and versatile.
It depends on what you're using it for. Every Cad Package has it's own little niche in specific markets. HUGE QUESTION!!!! but the BEST question!!!!! Think of it like shopping for a car. How much are you going to spend? How well, will it get you from point "A" to point "B" with the most comfort in the ride? How expensive -or- hard is it to fix and maintain? What's it going to cost to run it annually?
I have never used Creo. I pose that you should post a question in the Q&A section of grab cad asking the community on their thoughts on Creo Parametric.
I would recommend Solidworks, simply because it is capable of almost any task you would need a CAD software for, very complete and widely used. The only downside i foresee is the price of a license.