It depends to some extent on what you mean by "folded eventually"--- if they managed an exit, but it soon became obvious that the exit was way too high and the company crashed shortly thereafter, does it count? Or are you looking purely for companies that raised a ton of VC and then died, leaving the VCs holding the whole bag?

For the 2nd category, the largest I know of was kozmo.com, which burned through about $250 million in VC dollars, in about 3 years, before going under. Boo.com also managed to torch an impressive $150m in 2 years. Flooz and Broadband Sports deserve honorable mention in the ~$50-60m category.

The biggest immediately-post-IPO bankruptcy that I can think of was WebVan, which went bankrupt within six months of a $375m IPO, after having burned through about $800m in total funding.