What do you want to do, and how much experience do you have on long-distance trains?
I ask that because jumping into a cross-country train trip might be a bit much, if you've never traveled overnight on a train before, and it turns out that you don't like it.
Many people on this site (myself included) enjoy riding trains period, so our notion of the best use of points is the longest trip. This is not a normal way of thinking, of course. Who prefers flying a circuitous route with changes at various airports to a direct, nonstop flight?
Another way of thinking about maximizing value is to look at what it costs to book a train trip. I prefer to use AGR points to book trips that I could never justify paying for.
A case in point: the California Zephyr. Great mountain scenery, eyewatering bedroom prices.
If I lived in Albany and had 35,000 AGR points, here's what I'd do:
Albany-Toledo paid coach. Sure, it's most of a night in coach, but it's the beginning of your trip, and you'll be excited about traveling. I always try to arrange my travel so I go up in class of travel over the trip.
Toledo-Chicago-Martinez-Portland bedroom (30k AGR points) This gives you almost the entire California Zephyr, plus the Coast Starlight, which has a special Pacific Parlour car (another sightseer car) just for sleeper passengers. As you'll notice, the Sightseer Lounge car gets quite crowded. I'd debark the Zephyr in Sacramento, spend the afternoon there, and take an evening train from Sacramento to Martinez, but that's up to you. You could also continue your trip all the way to Seattle, but I like Portland better.
Portland-Albany paid flight.
You could certainly travel in a roomette for 20k AGR points, especially if you're traveling alone, but I really like the bedroom.
A random date in January gives a total for that trip of $2421, which works out to 8 cents a point. Pretty good redemption in my book.
One other thing: the cost in points to book a roomette or bedroom is identical, regardless of the number of people traveling.