A:
You specify "major" casinos, so with Caesars Entertainment and MGM Mirage International together owning about half the Strip*, and major stand-alones (here) like Cosmo, Hard Rock, LVH, M Resort, Hooters, Golden Nugget, Palms, Trop, Stratosphere, Westin Las Vegas, and the "Coming Soon" Resorts World Las Vegas (once-to-be Echelon) under the ownership of other corporations and banks, that doesn't leave much casino real estate unspoken for, especially when Boyd Gaming and Station Casinos (admittedly still half-owned by the Fertitta family) collectively own most of the major "locals" joints.
However, while things have come a long way from the era touched on in recent QoDs about "Lefty" Rosenthal and Las Vegas' mob days, there are still some independently-owned casinos on the Strip, including:
- South Point is owned by Michael Gaughan, son of the legendary Jackie. Simple.
- Silverton is owned by California-based real estate developer and billionaire Edward P. Roski, Jr.
- Venetian/Palazzo falls under the Las Vegas Sands Corp. umbrella, which is definitely a "big corporation," but it also approximately 52 percent-owned by Sheldon G. Adelson and family.
- What was formerly Barbary Coast, then Bill's Gamblin' Hall & Saloon, and is due to open in 2014 as Gansevoort Las Vegas, remains the property of Caesars Entertainment, although the hotel portion and its reinvention is now under the custodianship of New York boutique-hotel owner Robert Bernhard, while nightlife impresario Victor Drai will be in charge of the expanded and eponymous after-hours club. CET will still control the casino space, however.
- What was formerly the Sahara is now owned by SBE, the Los Angeles-based hospitality, real estate development, and "lifestyle" company founded and owned by Iranian entrepreneur Sam Nazarian. It's slated to open in 2014 as SLS Las Vegas.
- The majority owner of the Riviera is owned by Starwood Capital Group, which has a 75% stake in the venerable resort-casino, but 21% is held by Derek Stevens, who also owns (with his brother) the D downtown, and most the Golden Gate.
- While it could hardly be described as "major," Casino Royale remains significant not only for being privately owned, but privately owned by a woman -- grandmother, millionaire, and former owner of the Frontier, Margaret Elardi (although hotel operations are apparently now under the aegis of Best Western).
- Treasure Island (a.k.a. TI) is owned by billionaire and Las Vegas resident Phil Ruffin, who made history back in 2007 when he "flipped" the New Frontier, which he'd purchased in 1999 from Margaret Elardi, for $1.2 billion in a sale to El Ad Properties. The price tag for the 36-acre lot was the highest per-acre price in history of the Las Vegas Strip but six years later, the site remains undeveloped.
- While Wynn and Encore are part of the Wynn Resorts empire -- a publicly traded company -- since the ouster of his former friend and co-founder Kazuo Okada, Steve Wynn is, to the best of our knowledge, by far the biggest individual shareholder and as Chairman and CEO, he's definitely the "face" of "Wynncore," although that's obviously not the same as actually owning the joint.
*CET: Bally's, Caesars, Flamingo, Harrah's, Paris, Planet Hollywood, the Rio, and the Quad; MRI: Aria, Bellagio, Circus Circus, Excalibur, Luxor, Mandalay Bay, MGM Grand, Mirage, Monte Carlo, and New York-New York.
Update 06 June 2013
CORRECTION: The earlier version of this QoD erroneously stated that Ganservoort is now owned by Robert Bernhard, when in fact the property remains in the portfolio of CET, which will continue to run the casino aspect of the business.
No part of this answer may be reproduced or utilized in any form or by any means, electronic or mechanical, without the written permission of the publisher.