Music for 18 Musicians - A website tribute
The following is a list of the available full concert recordings available via Youtube with links.  In concert date order starting from the most recent:  

24th April 2016
- Students, faculty, staff, and alumni of the Lawrence Conservatory of Music, Wisconsin, USA.  A version with a 12 minute introductory talk is available here This performance was played on the 40th anniversary of the music's premier performance back in 1976.  On the "intro" version the first few minutes is a general "thankyou" but then Prof. Erica Scheinberg does an interesting introduction to the piece for the 21st Century listener, which includes the musicians playing some elements of the piece to assist.  Give it a listen.  I love the description of one of the musicians who says that playing 18 Musicians is like being in an ocean but still able to breathe.

5th April 2016 - Players from Temple University, Mobius Percussion, and special guests, Temple University in Philadelphia, USA.  Philip O'Banion kindly discussed the performance and answered some questions which you can read here.

3rd February 2016  - Sibelius Academy, University of the ARTS Helsinki, Finland
This performance was supervised by Russell Hartenberger, one of the original members of the Steve Reich and Musicians ensemble.   It starts off pretty fast but then settles down, indeed the end pulses seem to last longer than any version I can recall.  

25th October 2015A video of a complete performance from The University of Tennessee Contemporary Music Festival Closing Concert at the Cox Auditorium on 25th October 2015.  Filmed on two cameras from the audience.  The ending is interesting as the violin doesn't wind the piece up into a fade but the tuned percussion does.  

March 2015  - Bang On A Can Allstars/So Percussions/Cash Ensemble.  National Concert Hall, Dublin, Ireland.  
Kenny Savelson, Executive Director of Bang on a Can says We uploaded the video recently because it was a great performance, a lot of fun for all of us to put together, and we wanted to share it.  The performance took place at the National Concert Hall in Dublin, Ireland on March 7, 2015.  This and all the performers who participated are listed on the uploaded video.  The performance was part of a "Bang on a Can Marathon" concert curated by Bang on a Can co-founder/composer David Lang.  The short 'story' is that David Lang and Bang on a Can were invited to curate and produce a contemporary music festival weekend at the National Concert Hall in Ireland.  As New Yorkers, we decided upon a program of concerts that would feature some of today's most innovated New York composers and ensembles side-by-side with our contemporary 'cousins' in Ireland.  Whenever possible, we love to look for exciting opportunities to bring artists and audiences together, to collaborate and for obvious reasons (certainly for you and those interested in your site!), it was a perfect fit to have the festival end with a powerful coming together of Irish and American musicians to play Steve Reich’s legendary 1973 classic Music for 18 Musicians." 

12th April 2014L'Ensemble Intercontemporaine and Synergy Vocals from 2014

9th April 2014Eighteen Squared, San Diego, California, USA.  Great version in front of a small audience

18th August 2013- MJO Reich Ensemble with Steve Reich on the mixing desk, Lowlands Festival, Holland

2011- Eighth Blackbird, Indoor Concert, Museum of Contemporary Art in Chicago

A fairly slow rendition in a darkened auditorium. (Following review from Laura Cohen): The acoustics are unusual and highlight certain instruments that are not so easily distinguished in other productions. For example, this is a terrific performance for hearing xylophone 1 (Section II is outstanding), though xylophone 2 comes off relatively muted. Still, this is one of the best recordings for hearing many of the individual parts. The viewing experience of these performances can be frustrated by the unfortunate editing, since the camera is sometimes pointing away from the locus of the action. (I’m still waiting for someone to do an overhead video of the pianos in Section V.)

2011 Eighth Blackbird,  Outdoor concert, Jay Pritzker Pavilion, Chicago
Recorded at a huge outdoor auditorium in Chicago, the Jay Pritzker Pavilion, an astonishingly modern looking building which forms part of the millennium park. Looks fantastic. The audience is half formally seated and another bunch of people draped on the floor of the surrounding area.. featuring some families whose bouncing babies are jumped up and down to the rhythm of this wonderful music. The musicians themselves are dressed casually too. 
The group start off a bit nervously I think but then by the time we get to section 3a the energy levels kick in and they are well into a commanding performance. The cellist appears almost in a trance around this point of the performance. Section 5 appears to go well although I thought it seemed like a long wait for the pulsing instruments to appear, but I may be wrong. The pace appears to get somewhat hot from parts 6 and 7, but then calms down again with the fresh maraca player at section 8. At the end of the final pulses, as the violinist is left on her own, the audience can’t wait any longer and burst into applause as the piece is still fading away – shame really because the silence (shock?) of the lack of pulse is normally an amazing moment – but I suppose you can’t knock the enthusiasm of the audience for this great piece of music.

February 2012 - The Ready Made Ensemble.  Shopping Centre Campania, Naples, Italy
Something a bit bizarre from Italy.  Poor quality hand made video of a performance by The "Ready made ensemble" ... in a shopping centre!  Well it beats pan pipes doesn't it!  What an amazing idea.  The video is painful to watch and listen to but worth a browse if nothing else.  I like the way you are on an escalator at the start with the opening pulse in the background, wonderful stuff.

21st May 2008  - Ensemble Modern and Synergy Vocals and Steve Reich.  Japan.
A full recording of a brilliant Performance from Japan in 2008 - with Steve Reich on Piano, Ensemble Modern and Synergy Vocals.   This video is also available as a full download in good quality from the website of the 2008 Composium here (if you can find your way around the Japanese.)
Review from Laura Cohen: Despite the blurry camera, the editing is well done and gives the viewer a decent education on how the scoring works. This performance is fun to watch as the musicians rotate among instruments and also look to each other for cues (see especially the latter part of Section IX).