version 1 of the wiki has been complied by krazykanuck

Houston-Hobby (HOU)
There are no airline lounges here! Huzzah! *hits "that was easy" button*
There is a USO lounge post-security down the elevator near gate 44 (Southwest side), open from 9am-9pm; access is for military members (active, guard, reserves), retirees, and dependents (normally anyone with a valid DoD ID card). There is a small food selection, many snacks, and sodas/juice/coffee available along with computers, TVs and sleeping chairs.

Houston-Bush Intercontinental (IAH)
First a couple basic comments:

Please do not ask "can I get to Terminal X to Z?" The answer is yes. Every terminal at IAH is connected airside by the Skyway train, and also connected landside by the underground hallways and tram. IAH is extremely efficient to get around. I'd be surprised if it took more than 20 minutes to get between the 2 least accessible gates.

You can walk airside between terminals B, C, D, & E without the Skyway. To reach A from those four you need to use the Skyway.

Alright to the lounges:

Priority Pass

IAH is home to 2 Priority Pass accessible lounges, both of which are located in Terminal D (hours of operation are as of 2/8/18):

KLM Crown Lounge (open from 6am-9pm daily)
Air France Lounge (open from 12pm-5pm daily)

IAH also has 2 PP restaurants (added 9/13/18)

Cadillac Mexican (Terminal A)
Landry's Seafood (Terminal C)

American Express

IAH is home to an Amex Centurion Lounge, located what could double as a bomb shelter, also in Terminal D. Current access rules permit complimentary access to all Platinum and Centurion cardholders and 2 guests. Please find all discussion, FAQs, and ask all of your questions specific to that lounge in the dedicated thread housed in the Amex sub-forum:

Amex Centurion Lounge IAH [opened 24 June 2016]

United/Star Alliance

IAH is home to a litany of United Clubs. They inhabit every terminal of IAH except D. Kindly direct all of your "What United Club..." and "Can I get into the United Club..." to these threads, which live in the United sub-forum, and I swear the answer is likely already there or will be answered quickly if it isn't: United has a lounge in Terminal A that is the smallest of their collection at IAH but is commonly used by Star partner Air Canada in A North and of course by the few United Express flights using A north daily.

IAH: United Club Lounge - Which is better lounge at IAH? Lounge renovations?

Consolidated "United Club Access Questions" Thread

The Polaris Lounge is now open located one floor above the current Terminal E United Club with a separate entrance door.

Buried in FT is the answer to the question about *G members who have *G through their UA status, traveling within the US:
No Exec Club access for UA*G traveling domestic at IAH (see post #20)
This is different than for example the LH lounge at IAD, where UA *G pax can enter even if traveling domestic.

American Airlines/Oneworld

IAH recently received an Admirals Club in terminal A south open at 4am (opened in 2017). Please find discussion here... I think. I get confused easily in the AAdvantage forum with its labyrinth of wiki's and master threads. But somebody will point you on your way.

Guide to Lounge Changes: Flagship Lounge, Admirals Club, etc.

Also of note, BA operates not one, but two lounges at IAH. Both located in Terminal D. Seriously this end of D should just be called lounge central.

There is the BA First Lounge, which is restricted to First and OW Emeralds. There is the BA Business lounge for Biz and the lesser precious stones.

I have personally visited the F lounge, detailed here: https://www.flyertalk.com/forum/29396739-post2.html

Those of the various OW stones may wish to peruse this thread:

Lounge Access Denied: IAH flying AA/F

Delta/Skyteam

I didn't forget about you Skyteam people. Try your luck at the KLM lounge. And yes, you have a thread too.

IAH KLM lounge... hardly worth the detour

And last and certainly least, the Executive Club

IAH also has a 3rd party lounge called the Executive Club/Lounge. All I know is it's in Terminal D. I've never been and I think it's where non-OW/*A airlines send their premium cabin passengers.

764toHI gives a brief comment below. In addition, this is the most comprehensive review I've seen for it: https://viewfromthewing.boardingarea...xecutive-club/

There is a nice, remodeled, USO lounge near gate D2 open from 6am until 9pm, access is for military members (active, guard, reserves), retirees, and dependents (normally anyone with a valid DoD ID card) There is a good food selection, many snacks, fruit, and sodas/juice/coffee available along with computers, TVs, local newspapers/magazines, and recliners and several sleeping chairs (donated new by Houston "Mattress Mac").