THE QUICK BROWN FOX JUMPED OVER THE LAZY DOG
The trick if you don't have a keyboard with no
ghosting issues whatsoever is to connect two keyboards to your computer at once, which is how I generated the above. No one said I had to use both Shift keys on the same keyboard!
More seriously, here are the results for several keyboards I tested around my house, sorted by number of keystrokes registered:
HP KU-1060 (stock USB keyboard included with my desktop):
H UCK BON FOX JUMPD OV H LAZY DOG
Built-in keyboard on an Acer Aspire One KAV60 (tied with the HP keyboard):
THE QUIC BROW OX UMPE OER THE Y O
e-Machines KB0511 (PS/2 keyboard that came with my mom's desktop):
HE QUIC BROWN OX UMPE OVER HE Z OG
Chicony KB-2961 (ancient PS/2 keyboard on my sister's ancient desktop):
HE QUIK BROWN FO JUPED OER HE LA DOG
Ideazon ZBoard ("gaming" USB keyboard with swappable key layouts, which was advertised with anti-ghosting features; I got it from a friend some years ago):
THE UICK BROWN FO JUED OVER TE LAY DOG
And with a flawless victory, the Dell SK-8110 (PS/2) connected to my dad's desktop:
THE QUICK BROWN FOX JUMPED OVER THE LAZY DOG
Oddly, none of the keyboards tested seemed to have issues with spaces not registering.