We will be in Anaheim June 19-26. I'm still trying to figure out which days are best to go during our stay there. We have a two day park hopper pass. Should be interesting, I'm a little nervous.
I've only been to DL twice, but assuming you are only there partial days on the 19th and 26th and you want to go consecutive days your best bet is probably the 20th and 21st (Wed and Thurs). If you are there full days on the 19th and 26th then I think the earlier in the week the better, i.e. the 19th and 20th or the 25th and 26th. I would stay away from Friday - Sunday.
However, 2 other things to keep in mind. 1) You should wait until the hours come out. 2) We called several weeks ago and they said that the last day the "high school grads days" or whatever they call it is 6/22. So, there will be a lot of extra local high school kids there that week and then "high school only kids from 11pm-3am" those nights I believe. So, extra noise until 3am if your hotel is close enough to pick up park noise (like the Fairfield with a park facing room). It might be best to go the 25th and 26th if you can.
Perhaps somebody more experienced can chime in....