I'll be the fifth person to make that recommendation. I was allowed to propose a research project to my 8th grade history teacher. If he thought it was a good enough subject, I was allowed to opt out of class for the semester. I chose the missions of SA and the teacher thought that was a fine idea. I spent days on my paper, not just in libraries but crawling all over the missions and taking pictures. They were a treat, a deeply informative history lesson, and mostly empty. Perfect tourist fare at the time but YMMV since I haven't been back in decades and don't know how things might have changed.I'll reiterate The Missions.
I like The Menger but my recollection is that the rooms are too small and outdated and the "haunted" aspect is meaningless. If I had that trip to do over again, I'd stay in a modern hotel and just visit the bar at the Menger. That's about the only thing that's worth it on that property, unless you place a very high value on easy pedestrian access to the Alamo.And I think The Menger is considered "haunted".