If I had it all to do over again, I'd probably join the Corps and give that a shot. I didn't, and it sounds like your son isn't going to either, so here's some advice about where to live.
What hall (I prefer the term dorm) he ends up in will have a lot to do with what friends he makes and who he ends up hanging around with for the next 4,5,6,... years and who his buddies are after college.
The amenities of the various dorms are what most incoming freshmen go by, and it is generally a mistake. Modular dorms (mods) tend to be the most requested, and are the most expensive, but they have the least atmosphere. Students tend to go into their room and close the door. They don't hang out with their neighbors as much, and aren't generally as social. On the other end of the spectrum, non-air, ramp-style halls (there used to be four, now only two, and one of those has window-unit A/C now) are the most social. Partly because of the architecture of the buildings and partly based on the non-air history, students were forced to have more interaction with their neighbors, if only for air flow in those hot months. Bonds of camaraderie form more readily when you interact more. Not to mention, these halls tend to be the cheapest, not only in overall price, but even more so in $/sqft, due to the relatively large rooms.
The other hall types track between these pretty closely by price, with a few exceptions. A good rule of thumb to follow would be to get him in the least expensive hall you can, and not just to save money. Since this post is already pretty long, I won't go into the semantic differences of each hall. I've considered the price a small factor in the following list, but the overall experience more important. Here's a summary of what I would recommend, in order:
-first tier-
- Walton -leader by a solid margin-
- Moses
- Hotard
-second tier-
- Moore
- Schuhmacher
- Hart
- Keathley-Fowler-Hughes (aka KFH or FHK)
-third tier-
-South Side (I don't recommend, but not bad)-
You can get the various bits of information re: dorm types (modular/commons/balcony/corridor/ramp/non-air-ramp) and prices from the materials that the Department of Residence Life and Housing mails to you.
I didn't include Lechner because it is only available to Honors scholarship recipients, by invitation - don't know if your son will get this invite. If he does, that's another topic altogether. I also didn't include Wells/Eppright/Clements because all these are co-ed and generally are already filled with upperclassmen, not to mention that all four of these are expensive modular style halls. Cain Hall is the athletic dorm, and is very nice (especially the food), but I would not recommend it for a non-athlete as a freshman. IMO, it would be better for your son to consider this hall after a year on campus in another hall. If I counted right, all of the other halls I didn't list are for women only, or have been demolished or changed to office space.
My opinion is only worth what you paid for it, but I think I am qualified to put it up here. I lived in a number of dorms as a student, and have kept in touch with some current residents of campus even through today. I lived in Appelt (1 semester), Lechner (2 sem), Schuhmacher (1 sem), Puryear (4 sem), and Moore (6 sem). I had friends or acquaintances in every dorm except for a few on the quad (which is generally corps housing). I also worked for the Department of Residence Life for 3 years, including a brief stint inspecting/measuring every type of dorm and type of room within them as well as the furniture styles.
Please keep in mind that whatever your son chooses will be fine. He will be with a whole lot of Aggies no matter where he lives on campus. Making sure that he goes to Fish Camp is more important than which dorm he chooses.