Every horse on my place gets: West Nile Virus, Tetanus, Rabies, WEE, EEE, VEE (we're down south so I've always given it, but up north you may not want to), Flu, Rhino and Strangles (IN not IM). My personal feeling is, vaccinations are cheap insurance, they won't guarantee a horse doesn't get the disease but generally they will get a much milder case of the disease and recover quicker. If your horse leaves the property and returns to it, if you're not going to quarantine him from other horses each and every time, then better to vaccinate.
I'm fine with doing a blood titer for various vaccines to see if they need a vaccination, if you don't want to just routinely vaccinate each year. I have a friend who trail rides a lot and that's how she does her horses. They all seem to do just fine with that routine. I have too many horses on my property to be able to efficiently do that, so mine just get vaccinated 30 days before the first mare is due to foal.
OOOPS, forgot to address the coggins issue. I pull Coggins on every horse, every year. It's the law in this state and at the places I ride, they require you to have proof ON you of a negative Coggins or they will send you home.