Do You Collect Coins Or Plastic Slabs?

True, dat! Especially hard to photograph slabbed proof coins...

I prefer slabs. I also like my paper money graded by TPG as well. It is not that I can't grade I feel that it protects the coin and bill better than if it was in some flimsy flip. I buy raw too and I will not pay more for TPG coin or bill, but if the same coin was offered for sale at the same price and one was slabbed and the other was not, I would go with the slab 10/10 times.

When it comes top banknotes, it is easily possible to slab them yourself between two stiff flat sheets of perspex (lucite), and weld them together with tiny droplets of acetone at the corners.
If want to unprison them, just carefully chamfer cut the corners of the perspex with a hacksaw.

I'm am rather young, and so far my most expensive coin ended up at $65. (MS65 graded Carver half by PCGS). I like slabs because it makes storing easier (yes coins can tone in a slab but if my slabs are in a container I sleep safely at night)but also because I am incredibly OCD. The slabs offer a great way of protecting, insuring future liquidity, and also quickly identifying coins for storage.

I collect coins. Slabs have become, for well or ill, part of the 'hobby.'
I place hobby in quotes because to the best of my memory slabs were to make coins an investment
vehicle for the non-collector.
"To be traded sight unseen."
No collector believes that today. "Buy the coin and not the slab" is stated here daily.

I have slabbed coins that were passed down from family to guarantee authenticity. And to sell.
I have cracked slabs to place the coins in an album.
I have done so based upon my own goals which are mine alone.
And I would not presume to suggest to another what course of action to take.
Except:
LEARN! And then learn more.
Finally, follow your own comfort level.

I collect error coins and Sample slabs !

I prefer my coins raw personally. I like to be able to look at the coin, to rotate it in my fingers (and I don't buy many coins in grades high enough for such things to matter - and not only due to that).

If I want to keep a coin safe, I put it in a tiny ziploc bag. Some might well consider it a primitive type of plastic slabbing already.
It's easily reversible, however - that is to say, it is very easy both to put a coin in a ziploc and to take it out (and of course if a coin is in AU or higher, I'd probably rather look at it through the thin polyethylene layer of a ziploc bag than risk damaging it with insufficiently clean fingers).
Most of the coins in my collection are normally located in ziploc bags (though many of these bags contain more than one coin).

The next step in slabbing is the flip - uncommon but useful; it's a harder version of the ziploc, protecting much better from the damage, but almost as reversible.
However, a flip puts a lot of restriction on the size of a coin that can be placed there; coins slightly larger than the ideal size won't fit at all, while coins slightly smaller end up bouncing all over.
My collection has, I think, perhaps three or four flips, most of them dating from before I joined CCF; more could've helped, but sources have been lacking lately.

The step after that - and by far more common than the previous - is the 2x2 holder; the body of the holder is typically made of some kind of cardboard, so it really only counts as a plastic slab due to the thin layer of polyethylene (or, rarely, some other plastic - they're pretty much indistinguishable in such contexts) over the empty cicrle in the cardboard.
It is not normally easily reversible the way a flip is; except for very rare cases, a coin bought in a 2x2 holder will stay in it, and a coin bought without such a holder acquiring one is rarer still. It also doesn't protect the coin from damage any more than a ziploc bag does (at least as far as damage to the fields goes - rims are protected much better).
It is, however, for some inexplicable reason, incredibly popular with coin dealers; leading to dozens upon dozens of otherwise great coins being put in ugly 2x2 holders, where one can't even look at their edge properly.

Finally, somewhat outstandingly, there is the one actual plastic slab in my collection. It is made of acrylic glass, held together with a bunch of metal screw nails, and contains about a dozen various German pre-euro coins (including several from the 1870s).
I bought it for only $7 (using the exchange rate of the time), and would've probably made more money than that just selling the coins in there; however, it is so beautiful - in its sheer weirdness if nothing else - that I just don't want to get rid of it anyway.
(Anyone still wants to say that they don't collect plastic slabs at all? I'm sure that many of them would've paid even more than $7 to get something similar.)

To end the point: I would've probably loved to get an example of a coin actually slabbed by TPG, but I just don't have that kind of money; I did, in fact, at one point consider buying a slabbed coin, but decided that I didn't want to spend so much money (IIRC, the store wanted $75).

Slabs were invented with two goals in mind:
To remove the subjective interpretation of the Sheldon scale, and to make coins an easier investment for non-enthusiasts.
The Sheldon scale is quite honestly kind of like Chinese stereo instructions for non-coin people. So to make it easier for dealers to push coins out to the non enthusiast, as investments, the slab is perfect.
It's also a continuous, never-ending bone of contention between collectors and dealers. One man's MS65 is another's MS68, and so on. Slabs help with this but as we know are far from infallible.