What should my first Chanel be

The one I'm considering is the first one on the spreadsheet.

I would recommend going to a store to see what jumps out at you. Also, the medium/large flap doesn't have much room inside because it has a double flap, so you probably want to put your stuff inside to make sure it all fits!

I'm thinking this is going to be my only Chanel (we'll see how that goes...) so I want something really classic.
 
It really depends on how you are planning to use it and what you need to carry in it. If for heavy daily use, I would suggest a tote. If for lighter use, I suggest one of the beautiful metallic reissues. Decide how you are going to use your new bag, then check out the reference library. Let us know what you decide. Good luck!