These are called "pangrams". Here's a fun one that's short and makes sense: Waltz, bad nymph, for quick jigs vex!
Bright vixens jump, dozy fowl quack.
The five boxing wizards jump quickly.
Jackdaws love my big sphinx of quartz.
Two driven jocks help fax my big quiz.
My ex gave pub quiz crowd joyful thanks.
Pack my box with five dozen liquor jugs.
When zombies arrive, quickly fax judge Pat.
Amazingly few discotheques provide jukeboxes. (5 words!)
My faxed joke won a pager in the cable TV quiz show.