I had some rubber ones from IKEA that were okay, but my son complained that they were the exact same size as his favorite glass and therefore useless. I bought some 8" round cork mats meant to go under houseplants and now we use those.
We also use junk mail or other paper/cardboard items destined for the recycling bin (or possibly retrieved from it).
I went to a wedding where the favors were lovely coasters. I use them when grownups visit, so once a year or so.
No coasters. It is baffling to me that anyone would continue to use a table when the very use it gets most, can ruin it. It is like owning a coat that is ruined when it gets wet, or decorative towels in the bathroom that will be spoilt when they get used; or a cat that is only for decorative purposes and will flay anyone alive who tries to pet it.
Imagine welcoming a visitor. “Hi, nice to see you! Welcome. Please don’t pet the cat, even if it approaches you. If you go to the bathroom, don’t use the towels hanging there, I’ll provide you with a towel you can use. Don’t put your drink on the table, use a coaster. In fact, let me put the plastic on the couch before you sit down.” .
All my Ikea furniture is designed not to need coasters. The same hard coating they give their laminate flooring, applied to a table, makes sure that normal use of a table keeps it looking fine.
I do use reed coasters when I put my hot pans on the table at dinner, though. A table doesn not need to stand the same heat a countertop or stove does.
Technically, those are trivets.
Huh? Is there a particular kind of glass/mug that gets condensation on it? I have never noticed condensation.
Mmm.maybe condensation only occurs on cold drinks, with added ice, and I hardly serve those. I mostly serve cool (fridge temp) or hot drinks, and they wouldn’t have condensation on them, right?
Also, no table can stand the constant humidity of a house plant. House plants don’t belong on tables, IMHO. The few times a housesitter did put the plants on the table (so they “would all be in one place and she wouldn’t forget to water any”) my table was ruined. It took all of my lessons from Miss Manners to hide that fact from my well meaning house sitter. 
As everything horizontal in my house is either glass, plastic, laminate, vinyl, or too high to reach, I have no need of the coaster hypothesis.
Thanks. Now there’s an English word I would’t have learned otherwise. (They hardly ever mention trivets in Hollywood blockbusters, do they? )
I enjoy a constant supply of icy cold beverages when I’m home. I’m never without an iced-tea, or a Fresca or a beer or just a glass of water.
Hydration is key.
It depends on the room temperature and especially humidity. I suppose where you live up in the frigid north, condensation isn’t much of an issue. Here in more temperate climes, a bottle of water starts dripping literally seconds after coming out of the fridge.
Yeah, me too. Also a few magazines that I receive but never pay for.
I have a variety of coasters and items that are used as coasters. I bought some plain cork coasters at a hobby store, I bought some sandstone coasters somewhere else, and I use various other items. For instance, back when my mother had a functioning brain, she thought that Reader’s Digest was a dandy Xmas gift, so I used to have a lot of RDs around. I read the little humorous anecdotes and a few of the articles, but otherwise used them as coaster. There’s also washcloths. And my good dining table has bamboo place mats, which are big enough for a dinner plate, a glass, and silverware for one person.
We don’t use any now, but when my wife was nursing, she’d leave behind round nursing pads where ever she happened to be nursing. I’d repurpose them as coasters.
Not very attractive blue and green striped plastic things. And one coaster I received when I left my old job, with the company logo on it… brings back fond memories. I’ve been meaning to get better coasters. I’ve even considered making some.
I guess I’m in this group. What’s a coaster?
We’ve got plastic ones from Pier 1. We used to have glass ones. Then we had a kid.
Then a couple of days ago she started biting the plastic ones so hard that bits are shaving off of them. I am now thinking about making some fabric coasters.
We have a bunch of mismatched ones. My favorite is a square of natural slate etched with a loon that I bought once on our annual summer trip to New Hampshire. (Though I think it was purchased at Chapman’s in Fairlee, VT.)
We’ve got a lot of wooden tables, so lots of coasters. Our friends have even complimented how “nice” they are 
. I bought some 4" stone floor tiles at Home Depot for like $0.75 each, backed with self-adhesive felt from Michael’s. Cheap, easy, and they look pretty damn nice, if I do say so myself.
We received 2 sets of sandstone coasters as gifts and I love them! No puddles on the furniture!! They’re only used for iced drinks, tho. Hot mugs are fine on the tables.
My favorites ones are these: http://ep.yimg.com/ca/I/mouserug_2218_175073739 But honestly I don’t even know where they are.
My ex lifted all the good furniture when he moved out, so I just haven’t bothered for the last three years. When Celtling gets a bit older, and the legal (custody) bills slow down, then I’ll get some nicer pieces and drag them out again.
A member of a doo-wop group that sang Charlie Brown and Yakety Yak.
I have a glass coffee table. When I set a drink down that has condensation (or if we get a hole in our lips and some of the liquid dribbles down the side), it leaves rings. The glass table is not RUINED OH NOES, but it does mean I have to get up off my lazy ass and clean the goddamn table.
So it’s not that my widdle table is a pwecious flower, it’s that I don’t like cleaning. 