Vacuum cleaners are like cars: They come in a range of prices, sizes and capabilities, and the second you buy them, they depreciate in value and performance. All this makes buying a vacuum a little stressful. What if you live in a small apartment, for instance — does it make sense to buy a huge, ultra-powerful machine? Does it make sense to pay $500 or more for all those bells and whistles?

We're not the only ones who want to know. Vacuum cleaners are one of the top-queried products on Consumer Report's Web site (www.consumerreports.org).

So on this 100th anniversary of the vacuum, we set out to get the down-and-dirty facts.

1. Carpets come first. According to the latest study done by the Association of Home Appliance Manufacturers, the majority of American vacuum owners have uprights (rather than canisters). "If you have carpeting, especially wall-to-wall, odds are you will be happy with an upright," says Bob Markovich, home and yard editor for Consumer Reports. "Carpets are a vacuum's toughest cleaning challenge, so you have to buy according to that challenge."

What if you have carpeting and hard-surface floors? "Many uprights will do a fine job on hardwood floors as well," Markovich says. On the other hand, people with hardwood floors throughout their house or just a few area rugs will find canister vacuums perfect cleaning partners. Canisters also lend themselves to cleaning stairs, drapes and furniture.

2. Extras, extras. Vacuum attachments come in handy for hard-to-clean spots. Just be sure you're getting the proper attachments for the job. "Select an angled or flexible tool to clean and dust ceiling fans and high ledges," says Georganne Greece, floor-care buyer for Sears. "A flat or low-profile tool is great for cleaning under low furniture. For homes with pets or staircases or both, turbine-powered brush tools are perfect for pickup."

3. Consider brands. Once you've determined yourself to be an upright or canister cleaner, it's time to move on to brands. Consumer Reports consistently finds Kenmore, Electrolux and Hoover to be strong scorers in their annual tests and reader-response surveys, although their recommendations vary depending on individual models.

4. Pay less. "When it comes to price," Markovich says, "do not assume that paying more buys you better performance or more reliability." In fact, some of the best vacuums fall in the midlevel price range. "If you're paying more than $300 to $400 for a canister vacuum, you probably aren't getting the best deal. And for the best overall uprights, you're looking at $300 to $350 — not $500 and beyond."

5. Mind the store. Whether you buy your vacuum at a large discount store or a small independent store depends mainly on where you place value versus customer service on your priority list.

"Our annual reader surveys include big-box stores and local, independent vacuum cleaner shops," Markovich says. Whereas independent stores rated extremely high on customer service and selection, they rated low on price. That same survey shows that among big-box stores, Costco had great prices but was among the worst in service and selection. "If you're willing to give up the in-store experience, consider buying from amazon.com, which scored very well for price and selection when it came to small appliances," Markovich says.