First was Browning A5 20 gauge under the bed, then a Browning Hi Power. Replaced for awhile with an AMT Government Model, but now I'm back to the (same) Hi Power.
IIRC the first gun I regularly kept in my nightstand was a p85 it was fairly quickly replaced by a BHP and that remained the main one for quite a few years.
Mosin-Nagant M91/30 was the first leaned against nightstand. Now an inherited Webley Mk V with .45 acp full moon clips, serves as permanent nightstand gun, as it did for the previous owner.
My first night stand gun was an old yugoslav sks, but if you're confining things strictly to the physicality of being on your night stand, that would be the Ruger SR22.