I have been in the pinball hobby since the 90's. I have owned SM, Tron, LOTR...I currently own AC/DC Premium, METLE, and GB Pro. It's all a matter of opinion.
I LOVE the original ghostbusters movie so that might have an effect, but I seriously believe that GB is in a battle for the best Stern ever. If it is set up right and the pitch not too high and original rubbers as intended it is just incredible.
The layout is as original as you can get and as far as people saying it is linear that is Not true, because you can choose if you would like to start modes at the left scoop, the main ramp, or the right loop. The only linear portion would be the modes themselves in each of the three options.
If you like the movies the quotes and the modes are just spectacular.
Not to take away from any of the other games as LOTR, SM, and Tron are great in their own right. Your feelings change a bit after you have owned them. I owned LOTR about nine or ten years...
In general, ALL awesome games and you cannot go wrong with any of them! Great luck!