The most amount of people in toy drives are donors - people who give away toys. Chances are that's what you're thinking about too.

However before you give away any toys you have to make sure to pick carefully.

First off, who are the toys for? Some toy drives are for poor children, others are for children in hospitals. The kinds of toys they need are completely different.

Poor Children
Poor children are , well, poor. It's quite possible they may not afford to buy batteries or any kind of further equipment. You wouldn't give a ps3 game to a poor child unless you're willing to also dish out a console and help for the electricity bills. You have to pick something that will last a long time with very little upkeep.

Sample toys:

Water guns. Best part is that they can be refueled away from home if needed. That's what communal bathrooms and parks are for after all.
Board games.
A huge set of building blogs. Whether you want to donate Legos, wood sticks, Knex , etc.. doesn't matter. Just be sure to give out a huge tub so that the child never feels a need to go buy more.
Outdoor games (soccer ball, badminton set, marbles)

Children in hospital.
Hospitals have electricity, and many of them do have game rooms with consoles. However some children are bed-ridden, and of those who are not, they may not be allowed to go outside much. Ideally the toys should be toys that can be used in a room, so no outdoor toys, nothing that is meant to run with, nothing that requires a child to break a hospital's rules.

Sample toys:

Board games are good for just about anyone.
Video games. Be sure to check what consoles the hospital have and if they don't have any, you could donate one or simply find one of those mini consoles. The ones that'll have tetris and other games built-in.
Dolls and Action Figures.

What else to think about
Age and Gender. While most drives don't single out an age nor a gender, you may ask to see if there is a majority. If there are most girls and than boys, you should probably donate a girl's toy. If you're really in a giving mood donate two toys.
Ideally you should try to come up with toys that are suited for most ages and genders.

Sample toys:

Etch-a-sketch. Ok, teenagers may not like this one that much. However amongst the younger children, it is popular whether you're 3 or 8, boy or girl.
Uno (and other simple card games). Simple card games can be played usually for a wide age group and therefore allow for great easy fun.

You need to figure out a few questions.

-Where will we host this drive?
-Do we need a permit?
-How will we get volunteers, donors, and promotion?
-Do we ask for actual toys, or for money so that we may buy toys, or both
-Who are the toys for and what limitations do we have to enforce?
-Where will we store the toys?
-What methods will will use to sort them?
-How do we deliver the toys?
-Do we rent vehicles or ask a local truck company to lend us one for charity?
-How to get at least partial funding for storage rent, vehicle rent, gas prices, and any possible future costs?