I think I've used just about every type of crate there is out there, and seen the rest of them at shows & trials.
The wire crates are what I used most of the time at show sites and at home. I tried several brands - General Cage, Midwest, and Kennelaire. It was a must to have one that folds, suitcase-style! General Cage used to be my fave, as it folded up in no time, but they don't make my particular crate anymore, so when I got Gracie, I bought a similar one from Midwest, and it's a good comparison. I would not have a Kennelaire in my house - they are escape-proof, yes (closing with a little twist lock which is nice) but in anything other than the very smallest size, the top and walls begin to sag fairly early in - not as high a quality as you'd expect for the price.
I've also used Vari-Kennels at various times for travel and at home. They are good protection for the dogs in the car, but they are exceedingly bulky (and I had a very small 2-door Nissan Sentra at the time) and hard to lug through motel/hotel lobbies without creating a scene. They can pop apart during an accident, though. I always used cable ties to strengthen the seam using my dad's (a cable system engineer) heavy-duty (think those zip-ties that police use for handcuffs) ones. I moved away from those after my accident, and could not lift either the wire crates or the plastic ones.
Once I had one dog again (my Border Collie went with ex by court order), it was my very small 10 year old Sheltie (12 pounds). He'd never been much of a chewer, and crated almost all his life, as he had been trained and shown in obedience, agility, and herding from about eight months on. We went to live with my parents and space was at a minimum. So I went out to Target, and found a very thin nylon pop-up tent style crate. It was perfect for him, and would fold flat and store behind a door. I soon quit using it, though, as when I had surgery and was recovering in a hospital bed in my parents' living room, he developed a love for being next to me on the bed. So the crate only came out for road trips, which my parents do a great deal of, whether they have to take gimpy only daughter and her tiny little growly dog or not. This thin nylon crate was EXCELLENT for travel, as it would fold flat. Neechee was never a big chewer, and when the crate came out, he was ready to get in it as soon as his green dog blanket was chucked inside.
Shuffle a few years forward, and I am living with 2nd hubby in our own home. We rescue Bela, a 20 pound Sheltie after a year of doglessness. So I drag my selection of three crates down from the attic, and see which Bela likes best. She does best in Neechee's battered old General Cage suitcase crate, which I keep in the bedroom (bad hubby doesn't "believe" in dogs on the bed

) When running out to the store for a few minutes, I'd put her in the living room in the old pop-up crate. Invariably, I'd come home with the crate sitting on it's back wall and a very piteous-looking Sheltie at the bottom. And that was no matter how I had it anchored! So I put it back in the attic. Bela was flat-out scared of the Vari-Kennel (plastic) - I suspect that she was kept in one at the puppy mill. So that went back into storage as well.
When we rescued Gracie a few months later, it was on the spur of the moment, and we had no time to prepare. But then I have a large collection of equipment, so I was sure I could make her comfortable for a couple of days until things could get sorted out. I put her in the pop-up crate, as she wasn't a big chewer. That is, until I came home one day to find the pop-up crate in the middle of the living room, upside down and standing on edge. Since I left it in the upstairs bedroom fully weighted down, I was alarmed. I look down into the crate to see a very small, very scared Gracie who had had a MAJOR potty accident all over the crate and was covered in it herself. After making sure she was OK, I took the crate, dog and all, outside and rinsed them both with a garden hose. Nothing hurt but Gracie's pride.
The next day, I got a package from Amazon. It contained a brand-spanking new Midwest wire crate including a sectioning wall for crate training. I have retired the old pop-up, but keep it for emergencies.