The BBC Sound Effects site offering has gotten plenty of online sharing in the past year. Can you imagine having access to 16k sound effects? This is a sound effects library culled from the archives of the BBC and its Radiophonic Workshop, a selection of sounds dug up from broadcast sound work. There’s both synthetic sound design and field recording work – sometimes not really identified as such. I know this, because I used what I believe is the edition of this that was once released on a big series of CDs. –Credit
You can also buy all 30,000 sound effects royalty free for around US$5000, but you can also get individual files for around five bucks.