Somebody asked when I mentioned it on another thread - it has been my labour of love since Summer 
Due to MN advice last year I mostly avoided branded/character stuff and went for smaller accessories that they will be forced to can be more imaginative with.
Anyway the box (84 litre Really Useful Box - couldn't afford a nice wooden one) arrived yesterday so I packed everything into it while DH tried on various items and wrote it down as I went, in case anyone wanted some ideas.
Foam monster feet
Generic hi viz waistcoat
Plastic shield
Witch hat and dress (bought just after Halloween 
)
Jester hat
Deerstalker hat (purely due to Basil the Great Mouse Detective obsession)
2-piece doctors scrubs, hat and stethoscope
Black Dracula cape
Plastic 'gold wreath' ancient Greece style (Hercules is another obsession)
Musketeers outfit - cloth hat, cloth 'boots', top and trousers and beard
Various headbands - some with bows, some with animal ears
Black rain hat
Elasticated animal noses/tails
Fifi flower headband
Chef hat, oven mitt and apron
Furry gorilla hands
Green net tutu
Shepherd headdress
Grass skirt with flower garlands
Pink cowboy hat
Red Indian trousers, headdress and waistcoat
Victorian apron
Sherriff top
Brown furry scarf
Big sunglasses
Massive shawl
Fairy dress with attached wings
Velvet leotard with tutu
Posh clip on tie
Chunky bead necklaces
Big flower clips
Pirate necktie
Feather boa
2 pairs plastic 'clip cloppy shoes'
Various bags
Princess jewellery and tiara
Yellow hard hat/visor
ELC light up wand
White gloves
Burglar mask
Beady scarf
Reversible snow white dress (the crowning glory and the main exception to the non-branded rule - DD has been desperate for one since starting nursery last year)
Shamefully I have no idea how much it was, but I figured this will last them (DD 4, DS 2) a long time. All from charity shops/random shop clearances and mostly ebay for ridiculously low prices.
HTH if you are putting one together :)