Every once in a while, I find myself browsing some very impressive paintings that are part of the commercial art market. Technically beautiful paintings, created to be sold as prints to the public (see thomas kinkade). Take a look at Michael & Inessa Garmash's works. Each painting is amazingly detailed and expressionistic. Emotions are pouring out of the works. I love the use of bright colors and palette knifes.
You can browse around the Paragon Fine Art site and see a number of artists and prints that they are offering. I think the works are very fun to see, and as an artist I am always interested in what is selling. I do find myself very glad that I did not get into a commercial side of art, which I got to experience with airbrushing motorcycles. It seems very easy for me to get uninspired when I am creating projects for other people, otherwise known as commissions. I do sell my bearded bunny prints, and therefore have experience selling prints on the internet, albeit small affordable prints.
If you like oil paintings, you should browse the Paragon Fine Art site and maybe even pattern your own artwork store on the store they have. You can also find great information on making your own prints, and selling artwork online.