OK, so only the middle pair is actually universal, but all three pairs of active-3D TV glasses on my head, and compared below, will work with all 2011/2012 Samsung 3D TVs, as well as with 2012 Panasonic 3D TVs.
So if you have one of those 2011/2012 Samsung or 2012 Panasonic TVs and want to watch 3D sources, you actually, for the first time ever, have a real choice in spectacles. The question then becomes, "Which ones should I buy?"
The short answer is, as always, "What do you want?" If you just want to get 3D capability as cheaply as possible, the Samsungs are a shoo-in. If you're willing to pay more for better comfort and durability, I'd recommend the Panasonics. The more expensive Xpand glasses appeal to a smaller niche than either: people who actually anticipate regularly watching active 3D on multiple TVs (namely, ones incompatible with those Samsung or Panasonic glasses) in addition to their primary 3D television.
The shorter answer is "I like the Panasonics best." If you're into 3D enough to actually be buying 3D glasses for the whole family, it might make sense to grab a pair or two of the Panasonics as primary ("daddy" and/or "mommy") glasses and as many Samsungs as you need for other viewers. For 2012 Panasonic TV owners who just want to dabble in 3D, the $20 Samsungs are as risk-free as you can get.
Check out the full reviews, arranged in order of rating below, for more detail. I also listed current Amazon pricing (Xpand's $20 RF dongle will be widely available in four weeks).
Panasonic TY-ER3D4MU ($55 each)
The Panasonic TY-ER3D4MUs are universal glasses compatible with the Full HD 3D standard and offer decent build quality and appreciably better picture quality than cheap glasses. Read the full review.
Xpand X104 YOUniversal ($90 each for large blue/black version with RF dongle)
For the narrow niche of viewers who need active 3D glasses that work with most 3D TVs regardless of brand, the Xpand YOUniversals are great. For everyone else, they're overkill. Read the full review.
Samsung SSG-4100GB ($19 each)
The Samsung SSG-4100GB universal glasses are cheap and fine for casual use, but an uncomfortable fit and too-open design mean 3D enthusiasts will want other primary glasses. Read the full review.
Looking for specs and pricing? Compare these active-3D glasses head-to-head.
For more 3D info in 2D, check out CNET's 3D TV Buying Guide.