It depends on the build. Generally running in the Chaos Sanctuary and WSK is more rewarding because of the final boss, but the monsters there are tougher for most of the builds. The areas not worth to run are Kurast temples (too small) and River of Flame (Stranglers don't drop any equip items, Blood Maggot youngs and Grotesque dogs don't drop any items at all). Sewers lvl 2 is also lvl85 area, but has only 1 bosspack usually, so I didn't include it in the list.

These areas are almost as good as lvl85 areas. Regular monsters here can drop from TC87 (high chance) too. Bosses can drop all uniques including Tyrael's. Only champions cannot drop Tyrael's and regular monsters cannot drop uqlvl=85 uniques. In lvl 83 areas regular monsters drop from TC87 (low chance) and bosses drop like Pindleskin - mlvl=86, TC87 (high chance). For example - Durance of Hate is alvl=83.

* Halls of Pain

* Halls of Vaught

==Not-so good areas for MF==