That largely depends on what models do you have and how much effort you're willing to invest in promoting them. Do you expect that selling 3D models would generate substantial portion of your income, or you just have some leftover models from various projects and you'd like to put them on sale for occasioanl pocket money? Anyway, in todays market, it's not enough to just dump your HDD content to marketplace and expect easy money. You need to work pretty hard to establish and maintain steady income.
Currently, i find cgtrader to be the best in all regards. Turbosquid is second, but steadily dropping, due to its outdated/shady marketing policies and outrageous commissions. The only thing that keeps them afloat, is huge traffic. Sketchfab is most rapidly growing marketplace at the moment, but its content is slightly more specific, comparing to aforementioned marketplaces. If you're into gamedev, then there's specialized marketplaces, like Unity and UE4 stores. If you're willing to take all your content promotion in your own hands, then gumroad might be interesting to you. Other players are not worth attention IMHO.
