I would recommend TOPs pellets as they contain no artificial ingredients. Remember that pellets are not a complete food and are not a replacement for fresh veggies, fruit and tree nuts. I make a chop for my birds and literally put everything bah the kitchen sink in it. Because it is chopped up small it is harder for them to distinguish; be choosy with the ingredients. An addition of a small amount of corn in it is always the first to be sought out and some tiny orborio pasta helps to soak up any moisture and also is an inducement to poke about/eat some.
I offer both Harrison's and Top's but Dora will normally ignore them...she has a range of fruit and vegetables, some seeds and a nut every day with a piece of pasta or seeded organic (no salt) cardboard. ....oh sorry crispbread as a treat.