Well I use to own a 2007 MINI Cooper S.
I custom ordered that one. I love how I can add pretty much any option I want in and/or leave them out to my liking. The price doesn't fluctuate as all MINIs are sold at MSRP with very little room to negotiate so there isn't really much of a premium cost in custom ordering a MINI.
Having the EXACT car I want is an awesome feature/option that not many manufacturers allow. MINI's literally have over 10 million or so different possibilities which I enjoy.
I currently drive a Mazdaspeed 3. I like it.. It is fast. But it is no MINI. The MINI honestly feels unique and doesn't feel like I am driving another car on the road. It has insane handling and I love the go-kart feel to it. I may actually be stuck on this brand for a while because I just enjoy it so much.
Another big thing is the people who drive these cars. I'm part of the local MINI club here in the Dallas area (Metroplex MINI) and I have met some of the greatest friends through that club. The social aspect and the people that I have met are irreplaceable and it is something I honestly never felt with my Mazda and the local club here nor my previous car prior to the MINI.
Some people aren't big on these cars but I always recommend people to drive one. They have some of the best handling and really nice get up and go. They are constantly rated well and it is because they perform well. They are small - So they aren't for everyone - But they are a blast to drive.
I did opt for the new model which is the 2 seater model. It is a bit less practical then a standard Cooper but I'm single and have no need for the 2 extra seats in the back which I rarely would use since there isn't much room anyways. Likewise the trunk on the 2 seater Coupe is much larger then the other models and it is brand new and unique which is a huge factor for me
EDIT: Oh and I always buy new. It is just what I do. Mainly because I like having the peace of mind of having a manufacturers warranty attached to it and having the free service that BMW/MINI offers for 3 years/36,000 miles. I'm just like that.. No idea why