Unfortunately, free spinners are just not worth it IMO.
I have tried most of the mainstream/popular spinners and here is my personal opinion.
1. WordAI (Turing spinner) ($50 per month with a half price discount available for the first month)
Great spinner but for the price, you won't notice much difference to the yearly discounted version of;
2. Spinrewriter ($77 per year)
This is probably my favourite spinner if you need to save time and still get some readable content. If you set it up right, you can get some decent readable spins but make sure the source article isn't too advanced.
3. Thebestspinner ($47 per year)
Not the best if you don't have much time on your hands but for really high quality spins, it is very good. You can check the uniqueness in the generate article tab which is nice and a handy addition to one of the above tools (which seems to be inaccurate when it tells you how unique the articles actually are)
4. Spinchimp (chimp rewriter)
I used to use a free version of this tool and found it did the job really quite well. May be worth checking out if they still do a free version.
Overall, I would say if you have the funds, spin rewriter is your best bet.
Update- Just seen chimp rewriter in the sig above and the guy says they still have a free version. I would recommend that as the best free spinner and sure it's come a long way since I used it. Hope the above helps anyway!