'Best' Receiver/What I would recommend.

What is the 'best'?

In this instance receiver.

Ive seen this question asked all over 'best' is subjective, what you mean is what is the best receiver for me. To get the most accurate answer, it helps to know what you are looking to do with your box, if the EPG (program guide is important), if you want a twin tuner and so forth.

Ive used the following -

DM500
DM800se

VU+ Uno
VU+ Duo

Openbox F3

I feel I could confidently recommend the 800se, VU+ boxes depending on circumstances and budgets, ive been pretty much out the game for a while so some of the newer boxes might be more suited for users.

The more info you give the better the answer you will get.

I don't like the Openbox personally, but my friend has one as a bedroom receiver and that was the best choice for him (money, and purpose of the box), and he is more than content with the role it serves.

This post is prolly stating the obvious a bit, but thought id chuck my 2 pennies worth in all the same.

The 500 is a great box for starting out, in my opinion.

The best thing to do is ask yourself

Is the Program guide important to you (you may not think so, but when you have an inferior one you will miss it more than you realize in my personal opinion)
Do you want to be able to record?
Do you want to watch another channel while recording?
Look at the features, addons you can Incorporate in some of the better boxes, do you want to be able to make use of these 'extras'?

This is what I would do if I was on the market again? If you have a question about a box ask in the corresponding section.

Buying a box is like buying a car lots to choose from, just because some boxes are different doesn't always make them better (or better for you) and there are some clear 'Porsche' or Lamborghini's out there (yes car models were chosen carefully :) )

Although, even after saying all that, unless you can't bare the SD limitation of the 500 any longer, then id take Caz's advice.