Well, I went through ANH the other day and came up with this:

Owen
 Cloak Tan
 Pantaloons Dk Brown/Black
 Long Vest Tan
 Unknown Shirt Black/Tan soles
 Decorated Belt, Black/silver

Luke
 Unknown Shirt, Long White
 Casual slacks, Tan
 wrapped? boots, Tan

ObiWan
 Cloak, Dk brown
 Unknown Robe, Lt brown

Leia
 White pleated dress

Han
 Formal shirt Tan
 Black Short vest
 High Quality Boots Black
 Workman's? Belt, Black/Silver
 Thin Striped Pants, Blue/Yellow or Red (Bad color on my copy)

Greedo
 Ribbed Shirt, Blue/Yellow
 Short Vest, Brown (Pants aren't seen)

Rebels
 black vest
 Med blue longsleeveshirts/pants

Rebel officer 
 Pilot's Jacket Tan/Tan
 Tan slacks
 Tan Shirt

END CELEBRATION
Luke
 Rugged Jacket Tan
 Longsleeve Shirt Black
 Comfortable Slacks Brown
 Uniform Boots, Black

Leia
 Plated Necklace
 Belted Skirt, White/Silver
 Unknown blouse

Of course the Rebel Pilots are wearing Orange Fighter Flightsuits, but you knew that.  :-)

I've noticed that Lando's Shirt from Cloud City is the Trim Lined Shirt  - Navy Blue

And then when he is a General in ROTJ he is wearing the Belted Jacket. - Tan with light blue Sleves

how about we try and come up with the best combinations using peoples suggestions...

Here's mine:

Luke Celebration ANH: Yellow w/cream or white trim Rugged Jacket

Black Sidebuttoned shirt

Brown Small striped pants with Yellow broken up stripe

Black High Quality or Uniform boots

Episode 1:

Nute Gunray, Trade Federation Viceroy, opening of episode 1: Dark red double robe, with orangish sleeves (not the brightest orange), gemstone crest in silver tones (closest you can get)

Padme on Tatooine: blue flared cuff shirt w/ med grey trim, belted vest in grey with blue belt, standard boots, pantaloons in about 1 shade off darkest black

Jedi: belted vest, trim lined shirt in browns. Qui Gon wears dark brown pants, Obi-Wan wears light ones. For pants, crafter's pants look good when worn under a cloak, haven't tried with a vest yet.

Episode 2:

Padme, arrival at Lake Retreat: Grand Ballgown, yellow top and either pinkish bottom or blue-purple (we can't have 3 colors like on her dress), I paired it with women's shoes as it looks like she's wearing flats, not pumps.

Padme, fireplace scene: black luxurious gown

Padme's wedding dress: intricate dress, ivory

Anakin: Black decorative vest, dark brown trim lined shirt, black high quality or uniform boots

Aylaa Secura (twi'lek jedi): Lekku wrap, revealing top, crafter's pants in either dark brown or black.

Episode 4:

Leia at awards ceremony: Loose dress, both colors white, plated necklace

Luke at awards ceremony: Rugged jacket (I ended up using a shade of orange, the browns didn't pop like the color does in the film), brown comfortable slacks, black boots (high qual  or uniform), black formal shirt

Episode 5:

Luke on Hoth: Vested jacket tan with white sleeves, tan pants (large pocket pants work), grey cold weather gloves, panelled boots (white ribbings, with grey)

Han on Hoth: Scout Jacket, navy blue (or a shade or 2 off of black, we don't have navy blue), panelled boots w/ white ribbing, light blue body, white cold weather gloves. Swoop helm looks ok but can't really make it in the same colors.

Luke, Dagobah: Reinforced work shirt, large pocket pants in tans. Olive muscle shirt if you want to go more bare.

Bossk, Trandoshan bounty hunter: heavy flight suit in default colors

I have notes on a couple more but have yet to figure out which specific items match closest.

I found something kinda comparable to the shirt Luke wears in a new hope a long vest over a leather trimmed shirt in the same color  looks similiar though not exact. It also has a similiar look to the shirts all the jedis wear but you can't put a cloak over it.

Princess Leia also wears a Brown Maidens dress in 6 I think with the Ewoks.

Not a hero costume, but a funny combo I came up with.

Scout Jacket - Red with a white scarf.

Any solid color pants - Red

Any small gloves - white or green

Uniform Boots - Black

Workmans Belt - Black with Silver Buckle

Warm Hat - Red with White trim

Get em on a fat guy with a grey beard and you've got instant Santa Claus.

Mossy.

Leia wears panelled boots with the jumpsuit in Empire Strikes Back. I didn't include her outfit in my list because I thought Blight had, I guess I should have checked again hehe

I actually had to start taking notes on the clothing in the films because when watching them again (we just got the original films recently so first time watching in a while) I kept thinking, 'hey, that looks like a *insert tailoring schematic here*'.