It depends on a lot of factors. The line you have been playing, did you flop the nuts or did you river it? Have you and the villain checked it down to the river or has there been a lot of action. Is the river a potential cooler for the villain? What is the villains image and what is your image? What are your EVs? How much information do you have on the villain in terms of his current hand and how he plays other hands? Just a lot of poker involved in this question in terms of trying to maximize value

If I had to go for a straight answer though, in the long run online you're likely to get more from a well-sized bet over checking unless you are playing with a lot of more experienced players who will think on 1 or 2 levels above the average joe on the internet. At that point, it's a different game in my opinion.