My husband and I recently purchased an office chair from Staples. We are very happy with it. It was pretty simple to put together and is quite comfortable.
These are exactly what I expected. Easy to follow assembly instructions but you may want another person there to hold the back in place while you attach it. It can be awkward.
I would have rated it higher except that the base could have been a few inches wider - to make the chair less likely to tip over. Otherwise it is a pretty good chair with lumbar support (that was missing from a number of the more expensive options).