Bobbing apples
spooky statues - like musical statues, but when the music stops they have to make a scary pose (Asda etc will have now-type Halloween compilations in)
Stick the spider on the web (so draw a spiders web on a3 black card, stick it up, then they have a go at sticking a spider on the web, blindfolded, closest to the middle of the web wins).
Draw a spooky face on a satsuma
Broomstick relay - asda/tesco sell broomsticks for around £2, I got a couple last year and split them into 2 teams, then they run round a pumpkin or something back to their team and pass the broom back to the next person.
Colouring corner if you can print out some Halloween type pics off the internet. Also I cut out spooky shapes and bunting shapes out of card (spiders, bats, witches hats, pumpkins etc) and they made bunting
Get some jelly worms sweets, and different colour jelly (think I used green, orange and purple or red), then make up one of the jellies, put some of the worms in a bowl, add the jelly and let it set, then go the same with the next two colours and rest of the worms.
We also did the mummy game mentioned up thread.
Oh and a spooky treasure hunt, - you can have gold / silver coins if you want as the Christmas choc coins are in the shops now, but also some gruesome finds, age appropriate
And you could have the option of a couple of spooky cartoons (scooby doo/ tom& Jerry Halloween DVDs are usually £3 in asda at Halloween)
Spooky themed pass the parcel
To be honest I've usually found they don't end up playing everything, as the time goes by so quickly. Last year ds1 and his friends loved the spooky statues (they were 7) Dd and her friends preferred the craft type activities (5): ds2 was 5 days old 
I'm hoping this year will be a bit easier, as the 8 year olds are a bit cool for too many games!!