Is the hollow Earth theory based on a sub-surface network of tunnels that link large caverns, or do they really believe there is a interior sun that lights a hollow core. This seems to have many problems, and wouldn't make a legitimate science fiction story, one that expounds upon truly empirical theories. I've heard of the tunnels leading to Tibet, but don't believe the whole interior could be hollow. How deep could such a system go and still provide a sufficient base to hold our tectonic plates and other sub-surface phenomenon?
I am not sure if you are asking which one is more plausible or wich one would be a better setting for a world you are building. You would have to specify what are you looking for.
In general terms I would always recommend the tunnel network. if you look at the Underdark in Dungeons and Dragons or the cyber-labyrinth in Tsutomu Nihei's "Blame" series. A tunnel system can hold any number of ambients, from claustrophobic passages to caverns so wide you can't see the wall on the other side. Hosting entire cultures of peoples that could be as primitive and isolated or advanced and networked as you want.
On the other hand Hollow Earth does not really differ so much from the surface, other that you can spy on the other side of the world with a good enough telescope. But mountains and seas should not be that different, and you have to explain how the gravity works and where does the sunlight come from.
My vote is for Tunnel Network.