Agree with nutribullet--get the 900 model that's around $100 with a Bed Bath and Beyond coupon.

Vitamix. Just spend the money.

We have a Ninja (don't know the model, it was around $100) and it works well. It has three blades spaced out vertically and is pretty powerful. Much better than the nearly-disposable blenders we used to get (including Oster). I've never used the Vitamix so I can't say how it compares.

I'm a marketers dream and have a Nutribullet. It has it's own glitches (the O Ring likes to shift sometimes), but for smoothies and salad dressings I find it to be perfect. Right size, you can just use the cup to drink, easy clean up.

invest in a Vitamix blender if you are seriious about smoothies. If you just want the occasional smoothie then your should be fine. I have heard very good things about the Ninja Master Prep (QB900B) which isn't a fortune like the Vitamix so I might get that myself until I have enough money to get a vitamix.

I just bought an Oster blender thinking it would be good enough to make smoothies. Tried it tonight and it really struggled to blend the frozen fruit. Not what I had hoped. Any recommendations for a smoothie blender? Unfortunately I'm not a cook, so truly this would be just for smoothies.