http://www.freearticlespinner.com/ does halfway decent spins. I don't recommend spinning but, if you need it, there you go. It doesn't offer any control like declaring your own synonyms, but it is free and easy to use (paste in, push a button, then copy the spin) and is web based so no download.
My suggestion, if you are looking to save time but still maintain some quality, is to spin an article and then spend a few minutes going through it and fixing errors to make it a decent article for posting to article directories. Don't post an article that is just spun as Google keeps getting better at picking those out and penalizing them. That is part of the problem that happened with EzineArticles and Google Panda.
I would not suggest you any article spinner for writing articles. Fresh and Unique content is must for getting maximum from your efforts. You will not get fresh content from article spinners. for fresh content you have to write with your own mind.
I am with you in this matter. They not only do grammatical mistakes but also not much acceptable by Google.