Cars:
(female)
Most of the time they're OK, but if you mistreat them or don't service them often enough, they soon break down and/or turn into a wreck.

Copier:
(female)
1. Once turned off, it takes a while to warm up.
2. An effective reproductive device when the right buttons are pushed.
3. Can wreak havoc when the wrong buttons are pushed.

Critic:
(female)
What, this needs to be explained ?

Detective Novel:
(female)
Because you're not supposed to peek at its end the minute you pick it up.

Hammer:
(male)
Because it hasn't evolved much over the last 5,000 years, but it's handy to have around and is good for killing spiders.

Hot air balloon:
(male)
Because to get it to go anywhere you have to light a fire under it. And, of course, there's the hot air part.

Hourglass:
(female)
Because over time, the weight shifts to the bottom.

Kidneys:
(female)
Because they always go to the bathroom in pairs.

Magic 8 Ball:
(male)
Because it gives monosyllabic answers that usually indicate it did not pay attention to your question.

Penlight:
(male)
Because it can be turned on very easily, but isn't very bright.

Shoe:
(male)
Because it is usually unpolished, with its tongue hanging out.

Sponges:
(female)
Because they are soft and squeezable and retain water.

Subway (male)
Because it uses the same old lines to pick up people.

Swiss Army Knife:
(male)
Because even though it appears useful for a wide variety of work, it spends most of its time just opening bottles.

Tire:
(male)
Because it goes bald and often is over-inflated.

Web Page:
(female)
Because it is always getting hit on.

Web Site:
(male)
Because you have to wait for it to reload.

Ziploc bags:
(male)
Because they hold everything in, but you can always see right through them.