Ah, the holidays: Chestnuts roasting on an open fire, Jack Frost nipping at your nose … and a new HDTV so gorgeous it'll make your obnoxious relatives turn green-eyed with envy. Check out my tips and tricks for picking the best HDTV for your living room.

Bigger isn't necessarily better
Just because you can afford a monster-sized HDTV doesn't mean you should get one. As this CNET article points out, a giant TV will actually look worse if you sit too close, while sitting too far away from a smaller HDTV will make it harder to spot all that razor-sharp detail. So, do yourself a favor—get out the measuring tape and find out how many inches you (or your favorite movie fanatic) will be sitting from that brand-new flat screen. Then check out CNET's handy reference chart to find the screen size that’s right for you.

LCD or plasma, that is the question
What's the difference? Well, now that LCD and plasma prices are roughly in the same ballpark (price fixing aside), we're talking subtle (but potentially important) differences in picture quality. LCD displays, for example, tend to look better in brightly lit rooms, and in my experience, they deliver smoother, more film-like images than plasma (whether that's a good thing or bad is a matter of taste). Plasma displays, on the other hand, boast deeper black levels and wider viewing angles than all but the latest (and priciest) LCDs—a big plus, especially when you're watching a darkly lit show like "CSI" (the original, not the golden-hued Miami one). On the downside, plasmas are still somewhat susceptible to burn-in—residual patterns caused by static images like news tickers. The latest models come with circuitry designed to offset this problem, but you should still take some precautions, such as reducing your contrast settings and thinking twice before leaving CNN on all day.

What about rear-projection DLP HDTVs (and projectors, for that matter)?
Need a massive 60-inch HDTV for the rec room? Then rear-projection is the way to go. You can snap up a solid 60-inch model for under $2,000, compared to $3,500 and up (way up) for an equivalent plasma. The drawbacks? No. 1: Viewing angles (see below) on even the best DLP HDTV sets tend to be terrible. No. 2: Watch out for "rainbow" effects: distracting flashes of color caused by the spinning color wheel used in single-chip DLP sets. Rainbow effects are much less noticeable on three-chip DLP systems, although some viewers (myself included) still report seeing the annoying flashes of color, so try before you buy. As far as DLP HDTV projectors go, the really good ones—the models that make you feel like you're in a movie theater—will set you back several grand (my favorites hover in the $9,000-$10,000 range); also, be prepared to invest in black-out curtains, as HD projection images look the best in complete darkness. Oh, and one more thing: good luck finding a projector with a built-in TV tuner.

Check the contrast
Nothing makes an HD image "pop" like deep, dark black levels—and by the same token, weak black levels (tending more toward gray) will make even a razor-sharp picture look dull and washed-out. LCD TVs are particularly prone to iffy black levels, although plasma sets are by no means immune. When you visit a TV showroom, don't be fooled by lush images of multi-colored hot-air balloons floating in deep-blue skies; instead, insist on seeing some darker images, especially anything set at night. Better yet: Bring a DVD of "The Matrix" or "Blade Runner" with you for comparison's sake, and avoid (if possible) showrooms with harsh overhead lighting—do your comparison shopping in a darkened demonstration room instead. And as for all those wild "1,000,000 to 1 contrast ratio!" claims in the brochures? Well, every manufacturers uses its own methods for computing contrast ratios (with a little help from their respective marketing departments), so they're pretty much useless for comparing across brands.

Eye the viewing angle
Most plasma and LCD sets look great when you're watching straight on, but the picture may become washed-out as you move to the side, especially with LCD displays. Some sets (usually the pricier ones, unfortunately) have better viewing angles than others. Make sure to check for yourself (walk all the way over to one side for the shallowest viewing angle possible) before you buy.

1080p or 720p?
Depends on the size of the set. For HDTVs that are 40 inches or smaller, you'll be hard-pressed to see the difference between 1080p or 720p. If we're talking 42 inches or larger and you've got money to spend (lucky you), I'd recommend 1080p—you'll pay more, but you can really see the difference, especially if you're planning on using a Blu-ray player.

120Hz or 60Hz?
Manufacturers are making a big deal about 120Hz refresh rates on their latest HDTVs—twice as fast as on older, cheaper models, and far more effective (or so they say) at reducing motion blur. But is it worth the extra dough? CNET has an interesting column that debates the real-world benefits of 120Hz versus 60Hz, and in the end, the reviewers felt (and I tend to agree) that the differences are pretty subtle, if not impossible to spot. (Oh yeah ... I can already smell the angry comments coming ...) A more dramatic "benefit" of a 120Hz refresh rate is the "motion-smoothing" effect you'll see on pricier HDTVs, which smoothes out the natural judder in film-based material. Personally, I hate "motion smoothing," especially when it comes to movies shot on film; I happen to think that judder (like film grain) is one of the qualities that makes film look like film, not video. But again, it's a matter of taste—if you like it, by all means, live it up (but be prepared to pay up).

HDMI inputs: The more, the merrier
My new Sony Bravia HDTV has three HDMI inputs: two in back, and one on the side (pretty much useless, since I have a speaker sitting right next to it). That means I'm using one HDMI input for my PlayStation 3 and another for my Apple TV ... and just like that, I'm out of HDMI inputs. Luckily, I use component for my DVR and (older-model) Xbox 360—but I'm now out of component inputs, as well. Granted, not everyone needs two gaming consoles and an Apple TV, but with all the cool new video boxes coming out, you don’t want to get stuck with too few HDMI inputs. (You could always get an HDMI switcher or an HDMI-switching receiver, but they'll cost you.). I recommend a set with at least three HDMI inputs in back, plus a couple of component inputs. (Not sure what I'm talking about? Click here for help.)

Bargain versus pricey: What are the trade-offs?
You'll find plenty of HDTV sets—plasma and LCD, big and small—that are well under $1,000, but remember, you get what you pay for. Black levels and viewing angles usually suffer the cheaper you go, and you'll probably have to kiss 1080p goodbye. So, priorities? Well, I can tell you this: My first 1080p LCD HDTV was a bargain model, and the resolution was awesome, but the black levels? Awful, and it bugged me every time I looked at it. If I had to do it again, I'd probably sacrifice the 1080p resolution for a better contrast ratio—but again, that's me.

Where should I start?
Full disclosure: I worked at CNET for five years, and Yahoo! Tech and CNET have a content-sharing deal. That said, I happen to think that CNET's TV reviews are among the best in the business—indeed, I've picked my last few sets based on their recommendations, and they haven’t steered me wrong yet. Another great source: The legendary HD Guru, one of the nit-pickiest videophiles on the Web. I also recommend the AVS Forum, which is chock-full of tips and advice from its unusually knowledgeable (and opinionated) members.