Relatively inexpensive: Saddleback leather

Hella expensive: Ashland

Both should be BIFL, both full grain leather. Both have a variety of size options. Ashland's leather is technically nicer, but it's hard to justify the price difference in BIFL terms. I believe Ashland is made in the USA and Saddleback in Mexico. I've had both, recently upgraded to an Ashland after my Saddleback wallet was stolen. As I said, the Ashland is hella nice, but hella expensive.

Oh, and don't forget to treat your leather with a quality cleaner/polish about once a year.