I have thought of this many times. For me, the essential features of the ideal rifle are:
Chrome lined barrel, at least 14.5"
Very effective Flash Supressor/MB postban
Simple gas operation, similar to AK or AR-18
Field-strips without tools
Uses mags that drop free (m16 style release too, not AK/HK)
Must be able to add scope
night sites (front post)
Ring in ring sights (like HK) with "L" flip for 200&350 Yds
Overall length less than 34" (stock open/extended) 30" if bullpup
Weighs less than 7.5lbs
Reliability between AK (reliable as gravity) and the current M16A2 (pretty damn reliable if not abused)
And yes, I know my AR-15's gas system is not that bad, but it is a real bi+ch to clean, unlike the AK
I personally would like to see this offered in a bull-pup config, from a US maker. Saddly, I doubt this will ever happen.
As for whats in my closet, my Bushy 16" is getting close, but its go a long way ($$$) to go.