(FORTUNE Magazine) – You've heard about the Internet bubble and the hedge fund bubble and the real estate bubble ... but the muscle-car bubble? Yup, certain obsessions are booming--and may be headed for a bust. -- Corey Hajim

Celebrity reality TV shows

The Simple Life 4, Being Bobby Brown, Hogan Knows Best ... the list goes on. When Courtney Love reportedly turns down a reality show, you know the market has reached saturation.

Mega-yachts

A 150-footer used to be big; now the largest cruisers top 400 feet. The number of yachts over 100 feet (base price: around $10 milllion) has tripled since 1995, says Barb Tierney of the Yacht Council.

Fender Stratocasters

Hungry for a maple-neck beauty? What cost $175 in 1969 jumped to $17,000 two years ago and more than $30,000 today, says Richard Friedman, co-owner of New York's We Buy Guitars.

Big-screen remakes

An astonishing 41 film retreads of old TV shows and movies are scheduled to be released in 2005, up from 23 in 2004 and ten in 2003, according to industry tracker ReelSource.

Muscle cars

A 1971 Plymouth Hemi Cuda went for $500,000 five years ago, says Craig Jackson, CEO of classic-car auction company Barrett-Jackson. In January one privately changed hands for $3 million. "Guys have decided they want the crown jewel," says Jackson.