Basic wire cheese slicer like I grew up with
929473
This was exactly what I was looking for.  It slices cheese easily and is easy to clean.
3254784
LOVE IT.  Makes slicing cheese a breeze.  Holds together well and the wheel to tighten the wire after it stretches is a great feature.  We use cheese almost daily around here -- none of the processed "cheese food" or expensive pre-sliced cheese around here.  I've given them as gifts to my daughter and even sent one to my husband while he was stationed overseas.
912591
This thing is BIG & HEAVY, which is a good thing.  It has a strong wire which I see is easy to replace if needed, the roller is large which I think makes the slicing work better. You can adjust the thickness of the slices to thin or pretty fat. I let my hard cheese set on the counter a bit until it isn't rock hard them slice.  I can slice a whole block of cheese in just minutes. I slice for appetizer plates and for sandwiches with this.
It is replacing an old one where the wire came disconnected and it had no way to reconnect tight so I thought this one looked like it was better designed; it is. I would certainly buy again, but I expect this to last a lifetime.  So guess future purchases will be for gifts with a block of nice cheese.
2900575
I had one of these previously that I paid a lot more than $10 for but I don't really see any difference in quality.
If you have only used the handheld-type cheese slicer you need to buy this one now. The best part is it has a little slot for the cutting wire to drop into. This enables you to actually cut all the way through the cheese instead of rolling down to almost the bottom and just breaking off the cheese.
The marble is nice because it keeps the cheese cold and is very easy to clean.
It is a little bit hard to adjust the tension on the wire because the handle doubles as a set screw but it certainly gets the job done.
3732836
Quality made!! Slices through the cheese easily. Nice to get an additional cutting wire just in case.
3283656
This is a great lightweight easy to use cheese slicer. Have had it a couple months and really like it.
2498171
I have been using this type of cheese slicer for about 40 years.  This is an updated version from same company.  It is imported from Germany. Old one has held up wonderfully but I wanted a spare new one as well. The blade has been slightly modified but does seem sturdy. I purchased several for gifts for Christmas for friends and relatives.  Although advertised as slicer for sausage, lettuce etc. I would say it is really best intended for cheese. You can slice paper thin slices if desired or thicker as needed. The dial for setting thickness is not useful for me since I find it easier and faster to just rest the cheese block along back and push along with my hand as I slice away.  Works great for those Costco blocks of imported or domestic cheese although sometimes I need to divide into 2 pieces to fit on slicer. Although I am basing my review mostly on old slicer, I have now tried the new one and it seems to work as well. Cheese lovers will probably love this simple, efficient slicer as I have.

Update December 2016. I now have about 42 years experience using this type of slicer.  To address some comments I would like to say remember it is best as a cheese slicer although I sometimes use to thin slice onion or mushrooms.  Just watch your fingers.  Cut larger cheese blocks  to manageable size, wrap the rest for another day and slice smaller piece. You can get paper thin cheese slices with some experience by learning to push cheese gently into direction of blade while watching your fingers. Cleaning has never been problematic. Buy a dish washing brush with handle to clean. Drip dry in dish rack. I use this several times a week and bought my second slicer 2 years ago expecting my plus 40 year slicer to break at some point.  I now use both.
4859762
I purchased this cheese slicer because I had one just like it as a child. My husband and I enjoy good cheese and using a traditional knife just was not cutting it (ha!). This slicer glides through the cheese like butter...much quicker than a traditional knife. So glad we purchased this slicer!
2761419
While it does slice cheese, it's not very good at giving you consistent slices. Mine arrived with the cutting wire already broken, so I had to use the "spare" wire to replace it. The biggest problem is that the handle wiggles back and forth and there's no way to make it cut from a fixed, predictable position to get you the width of cheese you wish to cut. I try to push it as far left as I can, but as soon as it starts slicing into the cheese, it pushes back out, giving you either a chunk of a slice or a slice with an uneven surface. You can just use a knife and it'll be better.
2199020
The slicer works as I remember the others I've had through the years. Planes off a nice thin slice of cheese, but not too thin, I think its actually perfect.
I'm sure most of you know this, however, this is a cheese plane, not really a cheese slicer. This is more for harder cheeses like Parmigiano Reggiano etc, where you want to get a thin 'slice' of cheese.

If you are looking to get what I would call regular size slices of cheese (as in American etc.), then this may not be what you are looking for.
1082640
We've had a Prodyne cheese slicer for over 25 years.  We've never changed the wire, and it continues to perform well under heavy use.  The consistency in size of slices, and the ability to cut them quite thin are among it's attributes.  The quality of the marble and finishing is nice and not rough as compared to others making it easier to clean.  The handle is sturdy and not wobbly as I've seen in similar products. Although one person commented on the wire being too long, that can be easily adjusted: see instructions. I've purchased other makes of marble cheese slicers as gifts and ended up taking them back.  None compared with the Prodyne. I've just purchased a couple for gifts for friends who loved ours.
4968634
I like the overall quality of the product; though I was disappointed with how small it is, and the fact that the wire that was installed was actually already broken when I opened it.  I purchased this to upgrade my existing wood slicer that was getting a bit beat-up; however, as you can see in the photo, this is much smaller. If you are like me and purchase the large Costco bricks of cheese to slice at home, it takes a bit of finesse to make this one slice through it.  It did come with extra wire, so I was able to very easily replace the broken one. It is natural stone so it's very nice, though darker than I had hoped (of course no fault of the manufacturer,  you use what nature gives you).  If size is not an issue for you, this is a nice slicer.
4117068
I like it!  Very accurate and even cutting .. Much more control compared to the typical wire cheese slicer,  and one more nice thing, it cuts a very wide slice.  I like the 2 different thicknesses that are easy to achieve. I think it is a good design.
2245764
This is a nice slicer for any home use. Was perfect for slicing up fresh homemade bacon and lunch meat. You cannot really shave items with this slicer so beware. It is a little noisy and the pusher could be a little better it is still a quality item and perfect for what I need.
3776636
I have used this model off and on for many years. Slices well enough with the exception the sliced food just fall off the back so you have to set the machine on or in a tray to catch the food.

The positive side is that it folds flat and take up and uses little space.

It is a fairly rudimentary design and of craftmanship so it's not designed for heavy use.
4390303
I had always used this egg slicer to cut mushrooms, as it is much easier and quicker for me than using a knife. After I moved (whereupon I no longer had access to the Westmark Duplex) I purchased a generic egg slicer from Bed Bath and Beyond. Failing to cut a single mushroom (and breaking it in the process), I decided to purchase another Westmark Duplex. Let me tell you- it's worth the price. My last one lasted 25-30 years  before the wires started popping (though it was still useable), and I anticipate this one will last just as long. It's solid metal and comparably indestructible to anything else on the market.
3150387
It works!  Watch some videos on youtube to master this slicer.  I was hoping for the original heavy stainless steel version.  Got the cheaper version.