Not sure what your budget is, but you might look at a reconditioned VitaMix. They're available on the VitaMix website and maybe on amazon.com.

My Ninja is doing well (it's the combo system) but Vitamix is the top end choice. You can also find them at a good price, with extended warranty terms, at Costco.

I don't use a blender, but I like thesweethome for recommendations:

http://thesweethome.com/reviews/best-blender/

VitaMix if the budget allows it.

Have had our Vitamix for a few years now. Feel very confident in recommending it to anyone. Durable, well built and nothing slows it down. Great machine for all types of mixing, blending, chopping, etc. NancyLouise

Your Ninja should still be under warranty. I've had mine for 4 years and I haven't had any problems with it.

If you are positive you want something else then a Blendtec or a Vitamix are the two professional blenders that are highly recommended.

Vitamix...I agree with others above. I have a had my Vitamix for over 2 years. It works great!! I started out using a Ninja and it broke down after two months of daily use. I took it back to Bed Bath and Beyond. I purchased it because it was half the price of the Vitamix. I learned quick that you get what you pay for. I decided to make the investment in the Vitamix and I have not been disappointed. I use it make smoothies, almond milk, and soup.