My first mat was from the Beth Bath and Beyond, I bought it as an afterthought while browsing for bath salts. It was the usual, most generic purple mat you can imagine, not even a brand name on it. You can see her here (right) in all its 10 year old glory. Almost intact.
Later on my mind convinced me that I needed a "manduka". I suppose what did me in was seeing all the Mandukas ventilating outside the windows in every Mysore street near the shala when I visited in '08. It seemed cool to me, and I wanted to join the club. Why? because "it's fun and it leads to a better life", like Jesse Eisenberg says in the facebook movie.
Before seeing the parade of mat curtains I was very content with my good old purple one, but not afterwards. So I searched, read posts, and consulted others. Many people seemed to swear by the black manduka, a favorite among Ashtangis,.
Frankly I find that mat very heavy. I believe the traction to be OK, as long as you are not sweating buckets, but not that much better than the old purple one. I ended up settling for one anyway, a green one because I wanted to be different. It smelled like some sort of plastic for weeks in spite of plenty of ventilation and even a wash, but finally the smell went away, and off I went in my cool new mat.
I love the mat for my home practice. The only thing that did not go according to plan was that I thought it would last forever, as I had been promised by word of mouth from countless sources. For example: my mat already has the beginning of a hole in the back (right where the down dog feet go) and there are threads coming apart on the side. Nevertheless of course I still use it and do not plan on buying another one, because for me having less is, these days, a lot more. I prefer de-clutering and few possessions, or rather, to own just what is needed.
A few months after I bought the brand new mat it came time to go to Thailand for a 5 week Teacher Training. The idea of carrying the Manduka through airports made me cringe, and the thought of buying another one (a lighter version) just for travelling did not make sense on my new minimalistic yogi frame of mind. And so the good old purple one came along, and she was plenty enough, although, I wonder if it made me look less cool.
Another interesting thing that happened along the lines of my relationship with mats is Pure Yoga. They actually provide mats, orange ones, the "Jade" brand I believe although half the time I do not even see a brand in them. The Ashtanga room has marroon ones, all other styles get orange. I am sure there is a code message there.
Once I also bought one of those Gaiam travel mats, but those are so thin that they really hurt my back as I roll back and forth mercilessly in garba pindasana. That (right) is Iyengar by the way about to roll into garba, picture comes from this site. So even though the travel mat is light and easy to carry I just browse the websites of hotels where I will be staying and if there are mats available then the traveling mat stays where it always has been: the closet.
I do not regret any of the mats I bought, but I have to say that if I was starting and did not have one, I would probably go for a light yoga mat that has the durability and the unpretentiousness of my very first one.
I have a hunch that detaching from the mat is one of the practices we go through in yoga.
These days I will practice anywhere and with whatever mat I can get a hold of, or not... Matter of fact, about a year ago I practiced on the cement surface by the pool in a Miami hotel, no kidding, I am serious about going through that practice, mat or no mat!
If you are very concerned about he environment, and who isn't these days, the Eco Yogini wrote an excellent post with mat recommendations considering Mother Earth, you can read it here.
For an excellent in-depth review of the mythological Manduka, read Grimmly here.
And yes I know, Mysore practice does not end at one mat, there are is also a second mat, a sort of towel which helps on the sited poses whenever we are sweating lots. I use the equa towel and here is why. And I have to say, I have seen women with really cool "Mysore rugs" as these are called sometimes but I can never find them online, perhaps I will never be cool!