You're correct in your observation that a lot of Las Vegas coupons tend to be twofers and it's something we've been asked about a lot over the years, but historically found vendors to be reluctant to offer 50% off as an alternative.
The good news, however, is that last year we made a concerted effort to pitch for the single traveler when negotiating our Member Rewards Book, with notable success. For example, you'll find 19 buffet coupons that are good for 2-for-1 OR 50% off. Looking for something a little more upscale? How about 50% off your entrée at T-Bones Chophouse at Red Rock (to our mind, one of the better steakhouses in town). Other dining offers good for one include deals at Arizona Charlie's Yukon Grill, Waverley's Steakhouse at the Cannery, Golden Gate's Bay City Diner, and Flame Steakhouse at El Cortez.
Entertainment-wise, there are 50%-off coupons for Defending the Caveman (Excalibur), Fab Four Live (Planet Hollywood), Men of X and Todd Paul (Hooters), and Fitz of Laughter (Fitzgeralds). All the gambling matchplay and slot-bonus coupons are good for a single traveler, as are the hotel-room deals, rental-car discounts, not to mention some of the drink offers, and a whole bunch of other stuff. Plus, of course, there's our famous 50%-off up to $50 at the Palms, which you can spend on yourself in all manner of ways and pay for your LVA subscription in one fell swoop.
So, whether you're in a couple or traveling solo, we recommend you take a look at the complete list of 2009 MRB (formerly POV) offers -- we think you might be pleasantly surprised.