MSoS
I had faced the same problem with preps during my second attempt.
For quants, I had gone through the GMATClub Online Maths book - it was concise, precise and had all the formulas I required - I found it very helpful. Also, I found Bunuel's Top 50 DS and PS problems documents very very helpful. They have all the solutions as well. There's a long list of documents in Bunuel's signature - am sure there is a wealth of material there. You have the
GMATClub tests as well, which contain a lot of 700+ level questions.
On verbal, I found the documents in whiplash's signature immensely helpful - the Brutal SC, CR sets and the SC guide. Also, I found the SC guides by spidey and Gayathri very helpful.
The GMATClub threads for CR, RC, SC and PS, DS (as you are already aware) are a great place to learn.
e-GMAT, mainly targeted at non-natives, seems to be a good value-add, from reports of many users here - you could have a look at their free stuff and see if they help, and then take a call on whether you would want to take their paid module.
All the best!
Santanu