If you buy only one seed, the black oil sunflower seed is the one to buy. It attracts more birds than any other seed. The black oil provides more oil for the birds' feathers than the striped sunflower seeds. The only problem I have with the seeds is during the summer when the bugs get in the bag; however, I have come up with a way to stop this. I put a cedar block in the bag of seed and voila...no more bugs.

Pros: Attracts many varieties of birds, easy to find

Cons: Shells on the ground

This is the only seed I keep in my feeders year-round. It is preferred by about 80% of the birds that come into my yard and attracts those that are migrating. The squirrels are also more than happy to clean up what is left on the ground.

Pros: Most birds are attracted to black oil sunflower seeds

Cons: Sprouts easily

This is Miss Mighty Mouse's favorite type of bird seed. Its affordable and if she likes it than its alright by me. I would recommend this seed for any bird owner or any person that has a crime fighting pet.

Pros: Gives her energy to fight crime

Cons: none that I can think of

I love how the Black Oil Sunflower seeds attract the birds, but I hate how there is so much waste and and sunflower plants popping up everywhere.
I will say, that it does attract many different birds.

Pros: The birds love it

Cons: My lawn doesn't

I never have any waste when I put out Pennington black oil sunflower seed. Numerous birds are attracted to it. Also, my chippy who lives in our retaining wall can't get enough of it!

Pros: Excellent seed to attract a variety of birds

Cons: none