I've put an asterix (*) by tights which come in extended sizes (a size 28+ or more than 350 lbs). I've included links to reviews by

First, checking the the hoisery/tights tag will get you tons of info and reviews from this community.
The fattastic
The elegant
The swoon-worthy
The glorious
The witty
General note for shopping in person: Target stores have plus size tights from Merona (review, review). Target also sells ASSETS by Sara Blakely (a cheaper version of Spanx), review. K-Mart carries Queen Latifah branded tights, and Sears has some plus tights. Their online presence does not necessarily reflect what is carried in the stores, and vice versa.
UK fattie
Plus Size Tights
* 'NEW' Plus tights w/ lycra from We Love Colors $15, fits up to 375 pounds, 51 colors. Here is a positive review from someone who weighs over 300lbs, and another positive review for these tights. See also the welovecolors.com tag. (This style isn't actually that new. It's ben around for over a year. However, the older style has received negative reviews, so be sure you order the ones that say "new style").
*Comfort choice opaque tights from One Stop Plus. 2 pack for $14.99-$17.99. Tights through a 8x (45-46"). Grape, chocolate, wine, black, navy, beige, cream, charcoal gray, & dark sapphire.
*Plus opaque tights from Roamans. From $14.99, sizes 1x-8x. Grape, chocolate, wine, black, navy, beige, cream, charcoal gray, dark sapphire. review
*Avenue body microfiber tights $8.90, fits up to 375 lbs. Black, vino, raspberry radiant, nighttime navy, dark cocoa. Review 1 & review 2. 2009's tights are different from 2008's tights in sizing (review)
*Just My Size nylon tights 1x-6x (Fits up to 400 lbs). $7.99. Chocolate, linen, navy, black.
*Sternlein Cotton tights (also available here in black only. $32 Fits up to a 4x (about a size 28/30, max hip 56"). review 1 review 2.
*Avenue body ribbed tights. $8.90, fits up to 375 lbs. Black, wild dove, cocoa.
*Diamond textured tights from Jessica London. Sizes 1X-6X, priced from $12.99. Black and cream.
*Cable sweater tights from Jessica London. Sizes 1x-5x, from $16.99. Black, chocolate, charcoal, navy.
*Lace patterned tights from Jessica London. Sizes 1x-6x, from $12.99. Black, white.
*Pointelle fishnet tights from Avenue. $8.90, fits up to 375 lbs. Black, nude.
*Vertical herringbone tights from Avenue. $8.90, fits up to 375 lbs. Black, wild dove, dark cocoa.
*Chevron tights from Avenue. $8.90, fits up to 375 lbs. Black, wild dove, cocoa.
*Danskin high performance tights (plus). 1x-4x (60" hip), black, pink, white and navy. These are available at many dance outlet stores online. It's worth googling for a good price.
*Old Style tights from We Love Colors $9.00 51 colors. Fits up to 2x-4x (330 lbs), butreviews are mostly negative. See also welovecolors.com tag.
*Old style black/color striped tights from We Love Colors $12. 51 colors 1x-4x (max 330 lbs). Same problems as the old style non striped tights (see above).
*Spanx 'Tight End' tights $26. Tights through a "G" (325lbs). Bright periwinkle, new navy, latte, plum perfect. Also available at Torrid for the same price.
*Spanx 'Tight End' tights with extra tummy control $26. Through a "G" (325 lbs). Black, charcoal, heather bittersweet.
*Spanx high waisted tight end tights. Through a "G" (325 lbs), $28. Black, bittersweet.
*Spanx patterned body shaping tights. Fits up to 350 lbs. chain stripe $42, corset patterned $28, trinket patterned $28, diamond patterned $28, paisley pattern $28, picket stripe $28,
HUE opaque control top tights $12.50 or 2 for $20. Size 1-5 (fits up to 300 lbs). Black, navy, espresso, graphite heather. Limited colors in size 4-5.
HUE opaque tights $11 Size 1-5 (Fits up to 300 lbs) Black, brown, port. review
HUE tights from Bare Necessities $12.50, size 1-4 (fits through 250 lbs). Limited colors in size 4. Apple red, atlantic, baltic, black, bourdeaux, deep violet, espresso, flax, geranium, ivory, navy, steel, verbena.
Hue Opaque control top tights from Bare Necessities, $12.50. Black, deep orchid, espresso, graphite heather, harbor, ivory, mink, navy, tobacco, tornado. Size 1-5 (fits up to 300 lbs) Limited colors in size 4-5
Classic tights from Lane Bryant $16.50. Black. Fits up to 300lbs.
Control top tights from Lane Bryant $16.50. Black, cedar brown, heather charcoal, regal purple, red. Fits up to 300lbs
Ribbed Fashion tights from Lane Bryant. $18.50, fits up to 300lbs, black only.
Diamond stripe tights from Lane Bryant. $18.50, fits up to 300lbs, black only.
Just My Size silky tights $18.27 for a four-pack. Fits up to a 4x (300 lbs). Ivory, black, grey, very navy, brown
Just My Size cotton blend tights $8.99 (cotton w/ nylon/spandex). Fits up to a 4x (300lbs). Black, grey, very navy, brown. review
Leg Avenue Plus Stripey tights. $7. A variety of colors. Fit up to 250 lbs, and less than 5'9".
One Stop Plus control top tights, $9.99, graphite, cobalt, pink, espresso, wine, olive, navy, charcoal heather, brown heather. Size 1XL-3XL (5'3”-6'0”, 235-300 lbs).
Lands End control top plus tights, $18.50 for a 2 pack. Black, charcoal heather, spice brown, true navy. Size 1X-2X (255 lbs).
Lands End women's matte tights $18.50 for a 2 pack. Black, charcoal heather, spice brown, true navy. Size 1X-2X (255 lbs).
Eddie Bauer control top heathered tights $12.50. Thru XXL (XXL: height 5'4"-5'9"; weight 225-250 lbs). Charcoal.
Eddie Bauer has two types control top tights (max: XXL: 5'4"-5'9", 225-250 lbs.) for $12.50. Color varies
Wolford tights from Bare Necessities, $42-$58. Various colors, fit through 54" hip. review
Tights for people around 200lbs
HUE super opaque control top tights from Bare Necessities, $12.50. Size 1-3 (up to 200 lbs). Black, chianti, claret, cosmos, deep orchid, espresso, graphite heather, navy, portobello, rugby, sienna, smoke, twilight, verbena.
Opaque tights from Foot Traffic. $10, 3 for $25. Variety of colors. Fits up to 200lbs
Sternlein wool tights $36 Fits up to an XL (220 lbs). Black, charcoal, chocolate, ecru, nocturno.
DKNY control top opaque tights. $14.50 Tall thru 195. Black, chocolate.
Opaque tights from Sock Dreams $10.00 Black, brown, fuchsia, natural, olive. Fits up to 200lbs
Gap cable knit tights (*not* rib knit) in large will fit through an 18/20 says
Definitely give tights a try. Why have you shied away from them in the past?
This is sad news, because the tights they had last year were great. I think I'll be sticking to we love colors this year :/
Also, thanks so much for posting this!
I bought two pairs of tights from welovecolors.com and adore them. at 5'0" and about 210 with a big belly, I prefer the size A/B. I got one in each size and they're both comfortable, but the c/d is just a little long and needs to be pulled up from my ankles at the end of the day. But I can wear tennis shoes to work, so it doesn't matter as much to me. They're great bright colors that keep the color extremely well after multiple washings and are opaque enough to cover my large calf tattoos.
I bought a pair of brown ribbed tights frmo Avenue last year and they fit ok, but they ripped the second time I put them on, right along the crotch seam. Sucked.
If you order the Avenue Body herringbone/chevron/ribbed etc tights, they are NOT the same size as the We Love Colors tights. I fit best in We Love Colors C/D size, even though I am above the weight range for them. They fit up to 275, according to the size chart.
Avenue Body, however, has an accurate size chart. I wear a size E in those tights. Both brands fit this plus size gal pretty well, but they are NOT the same exact tights, as has been reported before.