Harry Hamster is reccomended by the NHC but some hamsters ignore the larger bits. Minnie loves the occasional bit of pasta and even a teensy sliver of cheese as a special treat. She also loves broccoli and red pepper (not the spicy kind)
Other foods to consider are JR farm dwarf (the syrian one is very low protein, fibre and fat IMHO so for a young hamster I would not use it, for an elderly ham though I would)
I'm actually thinking of mixing HH and JR Farm for Annie, using the JR Farm to add variety and dilute the high protein content of the HH