Digital movies have gone mainstream. Now it's increasingly easy, and cheap, to get movies online. Not only are these legal rental and download services more convenient — no more driving to the store or waiting on the mail — they're also frequently cheaper.

With so many services available, how can you make the best choice for your technology and movie-viewing preferences — especially when the details are not always easy to find? We've put together this guide, just in time for your holiday wish list.

Netflix

The original proprietor of VOD movies is still one of the best, especially if you're looking to simply supplement your normal movie-watching habits with VOD. Netflix's subscription-based model offers a low price and a wide selection. For the baseline plan of $8.99 a month, you get access to more than 17,000 streaming movies and TV shows along with your one-DVD-out-at-a-time rentals. The streaming movies are easily playable on many television sets, TiVOs, DVRs, and Blu-ray players. Netflix's only real downside is that it rarely has new releases available for streaming, reserving them for DVD/Blu-ray rentals.

Media: Streaming
Rental Storage: Unlimited (titles kept in your Instant Queue)
Viewing Period: Unlimited (watch whenever you want and as frequently as you want)
Price: Included in all monthly rental plans $8.99 and up
HD: Yes
Platforms: PC, Mac, Xbox 360 (Xbox Live Gold Subscription Required - 49.99/year), Playstation 3, Roku Digital Video Player, Select Blu-ray Players, TiVo HD DVR, Select Home Theater Systems, and Select HD TVs

XBox Live Marketplace / Microsoft Marketplace / Zune Marketplace

For the large number of gamers out there who own an Xbox 360, another option is the Xbox LIVE Marketplace. Its library nicely compliments what's available on Netflix (which also plays on Xbox 360s) and rentals are reasonably priced. Another big advantage is that Marketplace offers 1080p HD and surround sound, not available on most other VOD services. On the downside, its native digital rights management (DRM) means there's no way to pull movies off of the Xbox for another platform, and its purchasing system uses points instead of dollars, adding unnecessary cost and time to the whole process. However, Xbox LIVE Marketplace's expanding content means it shouldn't be dismissed just because of the hoops it makes you jump through.

Media: Download – Rental
Rental Storage: 30 days from download (as long as you don't start it)
Viewing Period: Watch as often as you want within 24 hours of starting
Price: HD rentals range from $4.50 to $6.00 (360-480 MS Points); SD rentals range from $3.00 to $5.00 (240-400 MS Points)
HD: Yes
Platforms: Xbox 360, Zune, PC

PlayStation Network

An Xbox 360 competitor, the Playstation 3 also features surround sound and 1080p HD movies. However, its VOD service outclasses its rival on many fronts. It boasts a larger rental selection and the option to purchase movies. In addition, PSN uses actual money, streamlining rentals and purchases. But perhaps its biggest selling point is that it doesn't have a restrictive DRM, making it one of the few services that encourages you to play movies on more than one device. However, the required Playstation 3 console makes this option too pricey for non-gamers, in our opinion.

Media: Download – Rental and Purchase
Rental Storage: 30 days from download (as long as you don't start it)
Viewing Period: Watch as often as you want within 24 hours of starting
Price: SD rentals range from $2.99 to $3.99, HD rentals from $4.50 to $5.99; SD purchases range from $9.99 to $17.99, HD purchases from $15.99 to $24.99
HD: Yes
Platforms: Playstation 3, PSP, and PSP Go

iTunes

Not just a music and podcast service, iTunes has a fairly wide variety of releases and frequently some of the better rental prices. However, to view movies you need to either plug your computer into your TV (making it a monitor) or purchase the Apple TV unit. In addition, HD here equals 720p, making it less appealing for those who want to watch their movies on a nice, big HD screen. While iTunes' DRM allows you to transfer your purchases among iPods, iPhones, and computers logged into your account, you can't transfer the movies to other devices.

Media: Download – Rental and Purchase
Rental Storage: 30 days from download (as long as you don't start it)
Viewing Period: Watch as often as you want within 24 hours of starting
Price: SD rentals range from $2.99 to $3.99, HD rentals from $3.99 to $4.99; SD purchases average $5.00, HD purchases range from $5.00 to $10.00
HD: Yes (but only 720p)
Platforms: Mac, PC, iPod, iPhone, and Apple TV

Blockbuster

Unlike competitor Netflix, Blockbuster allows you to rent and purchase individual titles without a monthly membership plan. It also boasts the most extensive library of new VOD releases and perhaps the widest range of platforms. Yet, depending on how many movies you view each month, especially in the "hot releases" category, the individual fees can quickly exceed the $8.99 monthly Netflix fee. In addition, purchasing VOD movies will run you about the same amount as buying DVDs — and at times can be even HIGHER than buying them from a brick and mortar store. One last, important note: Blockbuster's DRM system makes the service unusable on Mac platforms.

Media: Streaming and Download – Rental and Purchase
Rental Storage: 30 days from download (as long as you don't start it)
Viewing Period: Watch as often as you want within 24 hours of starting
Price: Rentals start at $2.99; purchases comparable to DVD prices
HD: Yes (but upscaled 1080i)
Platforms: PC, TiVo DVRs, Samsung Enabled Blu-ray Players, Samsung Enabled Home Theater Systems, Samsung Enabled TVs, Portable Archos Players and 2WiRE Set Top Box

Amazon

Price is key here: Movie rentals start at $.99 and usually top out around $3.99. Amazon also boasts flexibility, allowing you to download or stream movies based on your preference. While the service features HD movies, the selection is still pretty limited, even if it does often allow for 5.1 audio. Amazon uses an "Unbox" system that works better on Macs than PCs (where its can be clunky) and its DRM doesn't allow you to play movies on other devices.

Media: Streaming and Download – Rental and Purchase
Rental Storage: 30 days from download (as long as you don't start it)
Viewing Period: Watch as often as you want within 24 hours of starting
Price: Rentals range from $.99 to $3.99; purchases comparable to DVD
HD: Yes
Platforms: PC, TiVo, Roku, and select brand televisions