Ah, to be a millionaire and be able to enjoy the luxurious choices that might present themselves. Have you ever dreamed of floating along a river or lake in an exclusive houseboat, wasting away the hours doing all of your favorite things without a care in the world?

We're not suggesting that the mega-rich have no cares or concerns, or even more free time. However, we're certain they have bigger and better toys with which to relax and enjoy life.

The common bond between the elite and the rest of us, is spending time with family. Houseboats and yachts provide an incredible experience that give family time a new meaning. Owners who have families are more prone to buying houseboats, pontoon boats and fishing boats - all of an astronomical size, of course.

These houseboats are larger than most people's homes with square footage ranging from 3,000 to nearly 7,000 square feet. Of course, their size is limited by lake restriction and slip size, or we would be seeing motorized mansions, no doubt.

The tranquility of a houseboat is greatly enhanced by the luxurious and elegant custom details. Bathrooms that cost upward of $50,000, and large bedrooms with amazing views are common accoutrements. Making the houseboat a home away from home is generally the idea, so its guests can travel in the lap of luxury and comfort.

Customization is the name of the game, and the manufacturers are only too happy to supply the owners vision down to the last elaborate detail. Some of those details you might find fascinating like hydraulic lifts beneath master beds (to access storage space below or tuck away a laundry room, or something not often used).

10. Yet To Be Named: 3,150 sq. ft. $545,000

Being in the middle of a lake or river doesn't have to mean you're isolated. Have work to do? Plug in your phone's wi-fi hotspot and you are instantly connected while you sit at your built-in desk. Some marinas also have wi-fi, if you happen to be moored. Spending time on your home away from home doesn't mean life, as you know it, stops, particularly if you have the coin to move your favorite things onto your houseboat. Large screen televisions, game rooms, man caves and more can be found on these houseboats.  The square footage we are listing does include the inside and outside areas. In this case, 1,350 sq. ft. is the interior space, which is still roomy by many standards.

9. Yet To Be Named: 3,095 sq. ft. $575,000

How about a romantic evening around the electric fireplace with your hidden, custom stereo softly playing in the background? You have already popped your favorite date movie into your blue-ray, ready for viewing on your gigantic flat-screen LCD television. This extremely comfortable houseboat sports 1,295 sq. ft. interior of supreme luxury and style with maple accented with mappa burl from South America. As technology advances, so do the custom requirements of owners of these nautical wonders. This model is replete with a "zone" entertainment system so the captain can hear the music he/she wants while other music plays elsewhere on the boat.

8. Yet To Be Named: 3,000 sq. ft. $625,000

This fabulous houseboat features a master suite to die for - with granite-topped nightstands, a king-size bed and full-scale closets. It is all about maximizing the space. Some boats have storage areas beneath the beds and utilize every area to maximize the spaciousness and comfort of a houseboat. Generally, the houseboat's interiors at these prices are custom-tailored to the buyer. Recessed lighting is almost always included in the houseboat's design as it lends itself to an open feel.

7. Yet To Be Named: 3,500 sq. ft. $750,000

Complete with helipad, this little number is ready for get up and go in any direction. Not many owners would have the need, but as amenities go, it just might come in handy when your friends arrive for that fabulous party you're hosting. This houseboat has around 2,000 sq. ft. of interior living space that includes three state rooms and three and a half baths. This is truly a houseboat that anyone could love.

6. Yet To be Named: 3,550 sq. ft. $825,000

With 1,550 sq. ft. of interior space, this amazing houseboat includes a spiral staircase, burl-wood accents and recessed ceiling fans. The fact that it is not made with the most common lightweight houseboat materials (weatherproof aluminum) makes this vessel even more elegant and luxurious-looking. This might actually be considered more of a floating house, which is also starting to be the rage among the rich and famous.

5. The Ocean: $1.6 Million

This former barge turned houseboat is possibly one of the most plush houseboats in the world. The owner spared no expense modernizing this craft. With three large staterooms, three bathrooms, a super modern kitchen, separate dining room, a study, swimming pool and so much more. Did we mention the pop-up plasma satellite TV, which can swivel toward the hot tub or the bar? This could be a party boat as easily as a family vacation home, as the amenities suit all.

4. Mane Decision: $2 Million

This $2 million craft is replete with custom design and amenities. It sports mahogany cabinets in the 1,850 sq. ft. interior with eight-foot ceilings. Of course, you would not expect something this expensive to be without features such as an espresso maker, undermount sink and icemaker. However, what you might not expect is the mister ring that cools down your guests within a 300 sq. ft. area or a $50,000 bathroom with a wall of glass obsidian tiles and smoky glass inserts, and not to forget the rain showerhead. This houseboat protects its guests with a 44-foot long upper deck and black pearl granite bar that seats up to 16.

3. La Sorelle: $2.8 Million

Can you imagine a six-bedroom, six-bathroom houseboat that even has a retractable roof? You would definitely get your money's worth with this unique boat designed with a garden that measures around 1,302 sq. ft. that can be hidden during poor weather conditions. Did we mention two kitchens, three reception rooms and a large bar? La Sorelle is splendor personified and a houseboat most billionaires would love to add to their personal inventory of floating crafts.

2. La Dame du Lac: $3 Million

As the prices increase, so do the luxury amenities. This elegant houseboat is 100-feet long  and filled with some of everyone's favorite things. In the mood to invite your friends over for a movie? Perfect! There's a movie theater on board. How about a little wine tasting event? That will work, as well - with a full wine cellar. If anyone is running late or needs a quick getaway, there's always the helipad located on the boat as well for quick escapes or arrivals. La Dame du Lac makes houseboating look amazing, elegant and fun.

1. Sunseeker 115: $18 Million

What can a billionaire get for $18 million in a houseboat? Well, let's just say this houseboat is called the Ferrari of the Seas. It races, it's a house and also a speedboat. It is the complete package. With recessed lighting, top-of-the line bedding, woodwork, spacious design and comfort, the Sunseeker 115 is the quintessential houseboat for anyone who wants to get away and vacation on the waters a while. This boat will make you feel at home, yet make you feel like you are on a trip at the same time.