Originally posted by Franky2step I would take the 15, 40, and 100
I'll second that.
For me, a tele-macro prime is my most used lens ever (in my case, the Tamron 90 2.8)...you get a good focal length, aperture, and the ability to get great macros and portraits in one lens.
The 15 is the wide prime to use in landscape, environmental portraits, and urban shooting...it gets a lot of stuff in focus easily, so you can crop for composition later.
The 40 is a good standard focal length, to get indoors portraits (at a table distance) and candids. Since you're with your girlfriend, you'll use this one a lot (remember to turn off the beep on your DSLR for better candids).