What would cause my 1996 Sierra to need a boost every day.

I would recommend checking all connections. Verify that the connections at the battery terminals are clean and tight. Also verify connections at the starter. Check for loose connections or frayed wires. A loose or bad connection will give you symptoms you describe. Using another vehicle to "jump" your truck may give it the extra push it needs to get it started. It sounds like your alternator is charging if you're seeing 14 volts on the meter, but it wouldn't hurt to the get the battery load tested at the auto parts store.