This is how I came up with a good submit list.
I started out with the top LL's, then added 10-15 other LL's. After 1 month I dropped the ones that didn't list me or rarely listed me. After 2-3 months I looked through my stats to see how much traffic they had sent. If they had sent less than x per month, I dropped them.
Then I added 5-10 more and kept doing that until I had a list that would take me about an hour to submit to... or how ever long time you want to spend on submitting.
I have some in my list that are so-so... but I haven't had time lately updating my submit list and submitting sites
The "x per month" traffic is different from person to person. But I've set it to "enough traffic to send 1 signup per year per site" - which depends on your average CTR and your average conversion ratio.