Best place to buy a camera?

I'd recommend your local camera store Jessops or whatever, they're worth a visit before buying online, I prefer buying instore, if something's not available or in stock then Amazon or eBay get my my business.

I'd avoid online retailers that offer tempting prices that are just too good, I had a nasty experience with one and have read of other customers having all sorts of hassle, just be careful.

In the UK, buy from a shop, you have the same rights as online but it is easier to exercise them if anything goes wrong. Your camera is guaranteed for 1 year by the retailer. After that, the manufacturer has to give you 4 years guarantee against faulty workmanship. Total 5 years, 6 in Scotland. There are caveats with the long warranty but its better than paying for an extended warranty (which is the same as your legal - free- one) or losing everything because the year is up.

Stores are a dying breed and need your support. London camera centre, Jessops and Wilkinson are my favourites. In fact London Camera had the Sony A6000 cheaper than online prices. And they will demonstrate it to you.

The best place to buy a dSLR is at a reputable camera store nearest you. Warranty is free for one year. You don't need to buy extra.

The place it's sold will have no effect on reliability. Warranty is guaranteed by Canon if sold through an authorized retailer.

Buy it new, based on best price. That's all.

You can look at one of the Price Comparison sites.
However, I generally buy from Amazon. Their prices are pretty good; They might not be the absolute cheapest but I don't mind paying a few bob more for the customer service and delivery reliability.