The year-round staple
Black-oil sunflower seed is the single best all-purpose feed — it draws the widest range of visitors of anything you can offer, from cardinals and chickadees to titmice, woodpeckers, nuthatches, and goldfinches. Buying in bulk keeps a feeder reliably stocked, which matters most from October through April when natural food is scarcest.
Ground feeders
Doves, towhees, and juncos prefer to feed on the ground rather than at a hanging feeder. Scattering sunflower seed or millet in an open area near cover (a brush pile works well) gives them somewhere to retreat when a predator passes.
Thistle for finches
Goldfinches and pine siskins favor nyjer (thistle) seed in a tube-style feeder with multiple small perches. It's pricier than sunflower seed, but a full feeder can draw a dozen or more goldfinches at once.
Suet and peanuts
Suet is a high-fat, high-energy food that woodpeckers in particular rely on, especially in cold weather — but it draws a crowd year-round. Unsalted peanuts in a wire-mesh feeder are similarly popular with woodpeckers, titmice, and nuthatches.
Don't forget water
A reliable water source matters as much as food, especially once temperatures drop — many birds struggle more from lack of water than lack of food in icy weather. A small thermostatically-controlled heater keeps a birdbath ice-free all winter, and a drip attachment in warmer months adds motion that draws even more attention.
Feeder placement
Spacing matters: larger, more aggressive birds like Blue Jays will dominate a single feeder and keep smaller birds away. A few feeders spread across the yard, ideally with a large multi-side hopper feeder on a squirrel-baffled pole, lets more species feed at once without as much competition.
Quick reference — what draws what
Black-oil sunflower seedCardinals, chickadees, titmice, woodpeckers, nuthatches, finches
Nyjer / thistleGoldfinches, pine siskins
SuetWoodpeckers, nuthatches, chickadees
Peanuts (unsalted)Woodpeckers, titmice, nuthatches, jays
Cracked corn / milletDoves, juncos, sparrows, towhees (ground feeders)
Fresh fruitWaxwings, orioles, mockingbirds
Sugar waterHummingbirds, orioles