MacBook Pro 2011 miniDisplay port VS Hdmi - Best Adapter?
Your MacBook Pro is officially capable of displaying an external resolution of 2560 x 1600 pixels. Using a HDMI cable is not going to improve on this.

As far as the type of MiniDisplay port > HDMI adapter you opt for, we can't comment on one of those cheap HDMI adaptors you can find on Amazon as there are countless cheap adapters around and you'd really have to specify a specific model. However, what I can tell you is:


You don't need to buy the more expensive Apple one.
You should opt for a reputable well known brand if you're not going to buy an Apple one, not just a cheap and nasty brand you've never heard of before, as the quality of cable/connector can make a real difference.