There are loads of words I used to love when I was younger and I miiiiiiiss them :))

Numpty (recently resurrected)
Midden (scottish word for dungheap or rubbish tip ... often used to say describe someone who's dirty-minded or bodied) :))
Clatty (also scottish word for something dirty)
Golly (nominated by Brad as a much-missed word)
Drat - suggested by alec weston
Eejit - suggested by Andy
Minger - suggested by PurpleDragon
Cripes - suggested by alec weston
Pidgeon - suggested by steve_p
Shippon - suggested by ParsleySage
Twat - suggested by Meno ('wanker' isn't extinct) :))

Got any more? I'll add them to the list and we can work them into blog lingo (blingo?) :))