
UPDATED 12/ 19/ 07 **Bumping for relevence**
So the craftopedia is down for a bit, but I figure we can start here & when it is ready get our lovely mods to move it.
I do not pretend to know everything about every machine, or even everything about my own machine, I look for good commentary from you other experienced folks which I will incorporate into the original post with proper credit
I do know how to recognize a good machine, and I'm a pretty good comparative shopper.

Begin:
Buying a sewing machine is like buying a car, your level of skill, mechanical needs and budget dictate what you get in your machine. Sewing machines vary in price and quality much like cars. Bernina = Mercedez-Benz, Janome = Toyota, Kenmore = Buick, Pfaff = Volvo, Viking/ Husqvarna = Volkswagon. (Ok, most of the countries didn't line up perfectly, meh)
Knowing the reputation of the brand you are looking at, as well as recent reviews of quality for the specific model is important. If it's a good machine you will be using it a lot, if it's a poor machine you will not get far fast.
Some people have Hyundais and love them, some people wouldn't be caught dead in them. The middle of the road brands of Singer and Brother sort of fall into the Hyundai category.
So, to use the analogy above, would you rather have a gently used Mercedes? or a brand new Yugo?
Would you buy a car without driving it? Why buy a sewing machine someplace you can't try it out?
When you buy a car from the dealership there is an assurance of staff who can maintain your car correctly, any time down the road, same goes for a sewing machine store/ department within a store. Walmart has no service department, nor does Target. (don't get me wrong, I shop at both frequently, but not for sewing machines).
Like automotive companies, most sewing machine companies have levels or classes of the same thing. Or like Kenmore* & Husquavarna are divisions of larger companies that manufacture all kinds of stuff. Many Sewing exclusive companies have huge numbers of products, accesories and specialized optional components.
* The Kenmore name is owned by Sears, they actually choose products from other companies that meet their standards and make a deal to put Kenmore on the front. It's still good stuff and has the Sears reputation & service to back it up.
So Nitty Gritty:
Never sewn but want to learn how- what should I buy?
This is what you need from your machine:- straight stitch
- zig zag stitch
- reverseable stitching (most have a button or lever to do this, it's not a setting)
- a light on the machine
- bobbin winder
- foot pedal
- sturdy enough body that if it gets tripped over while sitting on the floor an adult's shoe won't crack the housing
- solid/ well placed footing or base so the machine does not rock or slide while sewing
Sewn some, learning more, want to do knits/ bags/ delicate garments/etc.You now need all of the above and:
- a stretch stitch
- a zipper foot
- a button hole function
- an applique or other wide foot
- a walking foot if quilting is a goal
- ability to drop the feed dogs if quilting is a goal
Brands that are generally considered good used:Singers over 15 years old (American built models)
Kenmore
Bernina
Viking/ Husqvarna
Janome that are less than 10 years old (Japanese built models)
Pfaff
Country of origin & general statistics on service:Bernina: Switzerland, has US based service company for big repairs. Excellent warranty. Many Authorized Dealers around the US, if you want a new one it's worth looking into these official stores. Pretty much the Mercedez of sewing machines, parts don't come cheap but they last so long you don't need to buy parts very often. Last sewing machine company world wide that is still owned & run by the original family. Budget line is called Bernette, seen as low as $US 199 on sale.
Pfaff: Germany, does not have US base for large repair service. Many Authorized Dealers across the US. Excellent warranty. Many put Pfaff in the same category as Bernina, a hair cheaper than Bernina. If Bernina = Mercedez, then Pfaff = Audi. Budget lines are Hobby and Smart.
Viking/ Husqvarna: Sweden. {need more info} Budget line is called Huskystar.
Janome: Japan, does not have US base for large repairs. Many Authorized Dealers across the US. Much younger company than most, but like Toyota and many other Japanese brands, have quickly established themselves as reliable machines. Budget lines are Florals and Gem Gold.
Singer: Until 19XX(eighty something?- need more research) American, still owned American but now produced elsewhere.
White: American. Has been around nearly as long as Singer. Long reputation as being good sturdy basic machines, does not manufacture as many higher end or fancy machines. Does produce Sergers and commercial machines as well.
Elna: German? Less popular in the US, I think more popular across Europe (chime in please, sisters across the pond

). High quality, non-beginner machines. Harder to find Authorized Service in the US.
{{ will come back to this soon!}}
** So I did some research, no wonder everybody looking is asking about Brother & Singer, that's all I could find with prices attatched!! The market is flooded with Singer & Brother machines, every discount wholesaler on the net has dozens of each! Which really should speak for itself, if those machines were selling in the original stores, there wouldn't be so many at the second tier sales places, right?