Animal crackers are ok but also try corn chips and maybe some BOSS (Black Oil Sunflower Seeds) I dont give mine treats as I have over 40 goats and you would get mobbed...if by chance you have just a few I just wouldnt over do it as they can get to fat on treats.
I tried giving my lady goats treats when I first brought them home. What a disaster it was. One goat got about 80% of the treats. I think it's because of the size difference-- two Nigies and a Lamancha. I haven't given treats since, except when one has to come out of the pen for medical/hygiene treatments, then I give them one apple flavoured horse treat. I like it this way, it simplifies things and keeps the goats focused on the rewards of human love.
Our goat eat just about anything I throw out to them.
They love bread, crackers(of all kinds), fruits and veggies, oatmeal, even tree branches that have fallen--they eat the leave off the branches.
They are on open pasture 24 hrs a day 7 days a week, so they constantly have grass to graze.
They also love pumpkin, squash, watermelon. They eat fallen apples, corn on the cob(stalks and all).
anything I throw out when in the garden...beets, turnips, lettuce, etc.etc.
They eat sunflower plants (heads, stems, seeds).
I only have 2 goats right now, but by no means are they ever short of food. They come running for treats even if by some slim chance I don't have any.