Digitalminx has some good pics and a lot of shitty low/med res stuff, but they do have a large number of celebrities. Bellazon is the same. Sites like Iheartwatson are ok - specific to Emma obviously so that's a plus. Most fashion/style sites often only carry low/medium quality and one or maybe two pics per event, but are good sources if you really want to know what designer dress/bag/jewelry/shoes/coat/etc Emma's wearing. Phun is good for paparazzi stuff. Planetsuzy has a good collection especially if you're missing older pics but alas many are no longer active (well understandable for pics from 10 years ago - that's a millennium in internet time lol). Too many celeb sites to name (GotCeleb, Fanpop, etc) but they can be ok - rarely the best quality but usually at least decent.
My two cents of random assessments for online Emma photo resources. LOL