I was actually already thinking about spending money on either the "gradedpianorepertoire.com" or the "pianostreet.com" database access. Does somebody has personal experience with these databases?
On the latter yes. If you want to see the sheet music as well, it's very useful and most print sheets are nice quality. But you do not need to pay to just browse though the gradings and then get the sheet music elsewhere, like from the free databases or books.
Gradings differ. Magrath's book has it's own, which grades pieces that are within the scope of an intermadiate/early advanced learners. The grading is from 1 to 10 so it has more levels than most gradings I have seen. It also has explanations on the pieces, even some teaching notes. Pianostreet uses from 1 to 8+ for the whole repertoire, so it's a bit more rough.
You can also print many different exam system gradings lists free from the internet, like ABRSM.
I have used all these in combination actually...