If we want to keep a main post for hotel stays, I volunteer to maintain the first post for it with the latest info.

Quick look at the GS FAQ shows that there is a 200 mile minimum per stay. Here are the minimums (excluding taxes) you need per hotel stay this year to meet the 200 mile minimum, based on chain. This assumes no elite status:

Best Western: Any stay earns 250 miles
Carlson: Any stay earns 250 miles at Country Inns & Park Inn, 500 miles at Park Plaza and Radisson
Choice: Any stay earns 250 miles
Hilton: 500 miles per stay (fixed miles) at all except Hampton, Homewood, and Home2, which require $200 (variable miles)
Hyatt: Any stay earns 500 miles
IHG: $100 most brands, $200 Staybridge & Candlewood
La Quinta: Any stay earns 250 miles, they might also allow points on third party website bookings such as Expedia. See note at bottom for more info.
Marriott: $100 (Marriott brand and better), $200 (all mid-tier and lower brands)
SPG: Can't find a link, but it is $100
Wyndham: $100, or any stay at a Wyndham Hotel or Hawthorn (these chains are 500 per stay)

"Cheap" stays for a hit: Choice Hotels lets you sort an area by price. AAA generally saves 10%. As an example, looking in areas near me showed the EconoLodge Absecon, NJ for $31/night on various weeknights. Choice seems to be the cheapest brand of the ones that offer fixed miles, although YMMV.

Staying more than six times during Grand Slam period: Look for promos that allow you to easily transfer hotel points with one or two stays. Remember you can only get one hit per hotel program with transfers. Example: Choice with their quadruple points offer means that a $125 stay ($250 at EconoLodge, Rodeway, Suburban, or MainStay) will get you enough points to transfer to US for a hit. See the transfers thread for more discussion.

If someone with a Choice Privileges account refers you (sends you a link to sign up with), you receive 1,000 points and they receive 1,000 points after your first eligible stay (essentially a stay that would earn points/miles). If you'd like a Choice Privileges referral email, PM me.

*Note that La Quinta Returns T&C state "Reservations booked through third-party Web sites, i.e., Hotels.com, etc., may not be eligible to receive La Quinta Returns points." They do not define which rates will and will not earn points on a third party booking. On the other hand, there are reports of phone agents saying that Expedia and the like WILL earn points. Book on third party sites with caution.

You cannot have more than one stay in one day, even across multiple hotels/brands, per the GS rules!