I just purchased the Teafco Argo Aero-Pet carrier, size small, in kiwi green. It's definitely not subtle (especially in the bright green color!) but I got it for airplane travel. Based on my research, it's the best for airline-approved bags, and it can be used with a seatbelt in the car. It's also virtually indestructable from the inside, which is good for puppies who like to dig or chew. I haven't gotten a purse-type carrier for sneaking Baxter into stores, but I'm partial to the Celltei Pack-o-Pet bags. I have to get something my husband would be willing to carry.
I don't get my boy for another 20 days, so take all of this with a grain of salt!