We had the wire crates with the plastic slide in bottom. Both Sam & Loki hated their plastic crates. They didn't like that they couldn't really see us. The wire crates were super easy to clean for house training. Now that they are trained, we actually have a gigantic fabric travel crate that we take everywhere - vacation, grandma's house if we go for like a holiday dinner... otherwise it sits in our living room. It fits in the back of our SUV without collapsing it and it's super lightweight - I can carry it assembled if I have to. Collapsed, it's super easy to handle. I put two big fluffy pillows on the bottom with fleece pillow cases I got at Bed Bath & Beyond, so it's easy to wash those all the time.
This is the one we have. Yeah I know it's ugly green, but they nap in it half the day by choice. They love this stupid thing.
Amazon.com: Firstrax N2-36 NOZTONOZ Sof-Krate...