I stick with Marriott for a few reasons.

Yes, I used to be an associate, and still own stock...so that's how I got started.
(Currently I am lucky enough to be a friend and/or family member of an associate....^ but that has only been the case for a couple months...and whatever rate that happens to be is not always the best....all of that is in the interest of full disclosure...)

Mr. Marriott's name is still on the buildings, and while things may have changed, the basic standards haven't......(much)

Now, they tend to have the most properties in places I go, in price ranges that I can afford. You know what you'll get (although sometimes it can get boring....)

I tried other chains last year, but either there wasn't a property near where I wanted to go, or the rate was too high.

Since I've been a Plat or Plat Premier for many years, I can see no point in switching now as I am very close to Lifetime Plat status.....

Overall I am treated very well. Sometimes things don't go well and generally any issues are quickly resolved. On those rare occasions where problems are not addressed quickly they can be escalated and again, they get fixed.

The Marriott Rewards program is, IMO excellent and I have gotten great trips out of the points....p;us having the points has come in handy when I needed a room someplace but didn't want to fork out 300 bucks.

I love the Spring Hill Suites....CYs are getting to be a waste and I really hate the new lobby/dining concept....the new SHSs are cool.

Residence Inns are neat as well...
I have realized on this current trip to Chicago that the CL is really just fluff. I didn't really use it, the lounge attendant was often MIA and when one was there, she was really not interacting with guests. However, there are some lounges that I really like (Bridgewater, NJ, JW Miami).....but I prefer the days when the attendant was someone who could provide info instead of sitting on his/her rear end fooling around on a cell phone. (PHL Ren anyone???)

I did want to test out other chains last year after Marriott made some changes and started telling hotels to not "overachieve"...and yes, Hyatt's free internet and free breakfast (in hotels without a lounge) was nice, but their rates were too high....

aaupgrade: i started my Marriott career at Roy Rogers.....got a couple years worth of prior service for that!!

LEED is the 'green' building rating system....try this....
http://www.usgbc.org/DisplayPage.aspx?CategoryID=19