I tend to stay with the roughly 21 inch carry-on size. My favorite is a Samsonite Spinner that I got for $129 which was the most expensive carry-on I own. I always wanted to get a nicer one but I could never afford a nice Tumi or Travelpro so I've been sticking with Samosonite and I've had pretty good luck with them. I've also bought some at Target and got a free luggage set when I bought my last car. Now for the cat - the d@#$ cat would use my bags for auxiliary litter boxes and at that point I just threw them out even if they were almost brand-new. (You can't get the smell out.)
I consider the suitcase as disposable and get decent quality at an affordable (for me) price.