I'd have a nice quonset style building filled with bikes. I'd sell BMX, Mountain, Road, and fixed stuff. No cruisers, but I'd be happy to order them from QBP and whatnot. Limiting myself to 5 brands, I'd go Iron Horse, Redline, Kona, Jamis, and C-dale.
I'd have a back room filled with so many spare parts it's ridiculous, and have a bar on the side that had 5 brews on tap at all times, two of them being the Sam's and Long Trail seasonals.