Chorus by ONYX

How to apply: Free at www.chorusrewards.com
Participating hotel brands: Amari, Hotels DeVille, Continental, Swiss-Bel, Husa, Lucerna, etc.
Number of hotels: 203 worldwide
Point value: US$1=10 points
Minimum points for free night: 5,000
To upgrade to premium/super premium/elite: Stay 10 nights/year for Orion; 20 nights/year for Centaurus/ No elite option
The Verdict: The fastest choice for a free room but a  limited list of hotels.

A Club by Accor

How to apply: Basic membership free at www.a-club.com/en/index.html
Participating hotel brands: Sofitel, Pullman, MGallery, Novotel, Suite Novotel, Mercure, Adagio, Ibis, All Seasons, Thalassa
Number of hotels: 2,300 worldwide
Point value: US$1=1-2 points, depending on property
Minimum points for free night: No free night but redeem 2,000 points for US$60 voucher for hotel food and service.
To upgrade to premium/super premium/elite: 10 nights/year or 2,500 A Club points for Silver; 30 nights/year or 10,000 A Club points for Gold;  60 nights/year or 25,000 A Club points for Platinum
The Verdict: Seems great except there are no free rooms and points can’t be transferred. 

Priority Club Rewards by InterContinental Hotel group

How to apply: Free at http://tinyurl.com/ns2px 
Participating hotel brands: InterContinental, Crowne Plaza, Hotel Indigo, Holiday Inn, Holiday Inn Express, Staybridge, Candlewood
Number of hotels: 4,500 worldwide
Point value: US$1=10 points for Crowne Plaza, Hotel Indigo and Holiday Inn, and 2,000 points per stay at InterContinental
Minimum points for free night: 10,000
To upgrade to premium/super premium/elite: 14 nights/year for Club Member; 49 nights/year or 20,000 points for Gold Elite; 50+ nights/year or 60,000 points for Platinum Elite
The Verdict: The widest choice of hotels but you need to spend at least a US$1,000 for a free night.

Preferred Guests by Starwood

How to apply: Free at www.starwoodhotels.com/preferredguest
Participating hotel brands: Sheraton, Westin, Four Points, St. Regis, The Luxury Collection, Le Meridien, W
Number of hotels: 850 worldwide
Point value: US$1=2 points
Minimum points for free night: 2,000 points. Four paid nights get one night free. 1,000 points can be redeemed for 50% discount.
To upgrade to premium/super premium/elite: 25 nights/year for Gold; 50 nights/year for Platinum Preferred; no elite
The Verdict: Some stylish hotel choices but you need to spend at least US$1,000 to enjoy them.

Marriott Rewards by Mariott

How to apply: Free at www.marriott.com/rewards
Participating hotel brands: Marriott, JW Marriott, Renaissance, Courtyard, Ritz-Carlton
Number of hotels: 3,400 worldwide
Point value: US$1= up to 10 points, depending on property
Minimum points for free night: 7,500
To upgrade to premium/super premium/elite: 10 nights/year for Silver; 50 nights/year for Gold; 75 nights/year for Platinum
The Verdict: A good choice of hotels and you spend only US$750  for a free room—the best deal in our book.

Gold Crown Club by Best Western

How to apply: Free at goldcrownclub.bestwestern.com
Participating hotel brands: Best Western, Best Western Premier
Number of hotels: 4,200 worldwide
Point value: US$1=10 points
Minimum points for free night: 8,000
To upgrade to premium/super premium/elite: 10 nights/year for Gold Elite; 15 nights/year for Platinum Elite; 30 nights/year for Diamond Elite
The Verdict: A slightly more budget brand but you still need to pay the same rates for free rooms.

HHonors by Hilton

How to apply: Blue-Level membership free at hhonors1.hilton.com
Participating hotel brands:  Hilton, Conrad, Embassy, Hampton
Number of hotels: 3,600 worldwide
Point value: US$1=10 points
Minimum points for free night: 7,500
To upgrade to premium/super premium/elite: 10 nights/year; 36 nights/year; no elite
The Verdict: A nice deal but not quite so many hotel choices as the Marriott.

Gold Passport by Hyatt

How to apply: Free at www.hyatt.com/gp/en
Participating hotel brands:  Hyatt, AmeriSuites, Hawthorn Suites
Number of hotels: 470 worldwide
Point value: US$1=5 points
Minimum points for free night:  5,000 at Hyatt, 3,000 at others
To upgrade to premium/super premium/elite: 15 nights/year; 50 nights/year; no elite
The Verdict: Expensive and a limited choice of hotels.