On the CTG episode that first aired May 24, 2008, Jeff Yarbrough from The Emerald Garden has the scoop on shade plants from hostas to new varieties of shrubs, groundcovers, and specimen accents.

Hostas: Queen Josephine, Gold Standard, Margarita
Hydrangeas
Crested leopard plant (Ligularia)
Heuchera (coral bells)
Abelia ‘Mardi Gras’  (variegated one)
Abelia ‘Rose Creek’ 
Japanese maple ‘Bloodgood’
Ajuga ‘Chocolate Chip’
Acuba
Japanese aralia
Taro
Plumbago (also check out Plumbago scandens, a shade-lover that blooms white)
Columbine (spring bloomer)
Bear’s breech
Aztec grass
Agapanthus
Cleyera

On the CTG episode that first aired February 18, 2006, Sharon Truett from The Natural Gardener showed several of her favorite plants for shady areas:

Pale Leaf Yucca (Yucca pallida)
Bamboo Muhly (Muhlenbergia dumosa)
Firespike (Odontonema strictum)
Manfreda 'Macho Mocha"
Squid Agave (Agave bracteosa)
Chinese Witch Hazel (Loropetalum chinensis)
Greek Pattern Plant (Acanthus mollis)
Xylosma (Xylosma congestum)

On the CTG episode that first aired October 1, 2005, Andrea DeLong-Amaya, horticulturist at the Lady Bird Johnson Wildflower Center, showed several of her favorite plants for shady areas:

Barbados cherry
Spiderwort
Columbine (Aquilegia chrysantha var. hinckleyana)
Columbine (Aqilegia canandensis)
Possumhaw
Beautyberry
Chile pequin
Inland sea oats
Pigeonberry
Turk's cap

For more ideas check Trisha Shirey's Made for the Shade tips.