It has long been discussed that High Def outweighs Standard Def in Advantages. I'm gonna have a bag at it and explain why I prefer which over what.
Lets start with the one everyone else knows. Standard Definition, otherwise known as DVD/like quality (720x480 resolution for those who want to know) is the standard these days. Every DVD and T.V channel claiming they're SD use this format. This is great if all you own is a normal T.V, and DVDs look great...right? Yes, DVD is pretty much still the standard (and still cheaper than BluRay... we'll get to that in a sec). If you want to reach a wide audience, DVD is the way to go. Most films and film-makers release in this format, and it holds great quality... Most DV tapes transferred to DVD don't even lose quality!
High Def, on the other hand... is the new player on the market. Sporting 1920x1080 resolution, or FULL HD (don't be fooled) quality. BluRay players are getting cheaper and cheaper now (compared to the $1000 they were when released) and you now have the option to view the film as the makers intended. Theres a swift distinction between DVD and BluRay (resolution for a start: 720x480 compared to 1920x1080), that being BluRay players provide clearer pictures on both standard and LCD/Plasma TVs. This is due to the HDMI outputs that most DVD players do not have. Those DVD players that do have HDMI really do not provide much better quality than the stadard RC cables. But lets get back to HD.
High Definition is about as close to film-like as you can possibly get at the moment. Film resolution is something like 2000xsomething... and so 1920x1080 is obviously quiet close to film. While, no... HD isn't better quality than film, it is cheaper and easier to use. In moviemaker terms, HD can be recorded to tape, hard drive, or even memory cards at costs that make Hollywood laugh. You could probably shoot a feature film on tape for $300 (If you already had the camera, the talent and everything else payed for... This is just tape costs) as opposed to film (which is like $400 for one 400 foot role of film...).
Basically, HD is the new SD. Standard definition will probably not survive much longer, but it's still cheaper to distribute in SD. The added ability of HD transfer to DVD via any computer is also what entices young filmmakers. HD is easy and quick to transfer straight off the camera and onto your computer hard-drive. Easier than that to edit and then down-grade to DVD. Besides the resolution change... you really don't lose any quality.
So whether your a film-maker, Videographer, or just wanna film little Timmy and his football game... HD is the best to go. HD cameras are dirt cheap (check out the Canon HV30 at $1300AU)... and you won't be left in the dark in six months when something new comes along.