Depends how much you want to spend. The grip ones e.g. triggerpoint are better, because as they have a plstic core they don't become misshapen over time. However, they are 4x the price of straightforward foam ones, so judge how much you will use it, over what period, and thus how often you might have to replace a foam one.
My cheap roller has taken months of use and abuse without showing any sign of wearing down or changing shape or firmness. Brand is Fit66, bought from Amazon, cost less than £20 including delivery charge. I'm very glad I didn't spend more on the dearer ones like the grid, cause I don't think they could be any better than my cheap one.
On the other hand, there are a couple of cheap blue foam rollers at my gym, and they're so worn out it's like rolling over a big marshmallow. Bloody useless!