Toyota, clearly the leader in the car industry with the most cars in the Top sold list in all genres. The Camry doesn't lose here either. With both Toyota and Honda racing to see who can be the most creative and plain at the same time, these car manufacturers are constantly looking for the middle of the road buyer. The buyer that makes up over 80% of the marketplace. The only thing these people are looking for is price, reliability, and safety. In the back of their minds might be looks, but pretty much that isn't the case.
With all this in mind, the Camry capitalizes on that majority in these easy and simple reasons:
Reliability
Low Price - Lots of amenities
Highest on safety and invented some of the many safety items found in most cars today
Highest resale value
Low parts cost
Now all these translate into something that most of the competitors of this manufacturer cannot match. Nissan lacks in reliability, resale value, and parts cost. Honda lacks in amenities, safety, and reliability (no timing chain).
For those who are wanting to purchase a Camry, I would wait just one more year for the new body style and some modest upgrades. The hybrid will be coming out very soon.