Pepper squeaks a lot... She makes sounds without even opening her mouth. When she does open it, she says "Ow" or "Raaaur" but that's about it. It's really cute!
Baby says "Mewow!" and "Now" and "Moom" and any number of other little sounds. Tiny says "Meh"--quietly. Neither of them quite have the "meow" down. Not that it matters; the're so cute whatever they say...
Sonic my Oriental boy not only says Miaow in a very exaggerated manner, he also says 'Hi', 'Mum', and 'Now'. Well I may be reading too much into the noises he makes, but he certainly says things that sound like those words!!!
Radar doesn't make much noise, he used to but he got sick last year and had a very inflamed throat, I honestly think it must have damaged his vocal chords because he's barely made a noise since. When he does, it's tiny beebs and chirps, and the closest he gets to miaow is a broken 'ow ow ow' noise.