Powerbot got me 87-95 wcing. Epicbot and simba got me from 49-87 but they were very unstable. The most I got out of either of them was 2-3 hours. I almost consistently get 8-10 hour proggies with powerbot.
Although it only has a 10-20 scripts in its sdn due to the fact that its been out less than a month, the scripting is clean and its by far the most stable free bot I've used. Along with rsbuddy(r.i.p)