Meteor or CL/Orb with Insight merc. Can tele everywhere with no mana issues. Chugging pots in MF runs is a no-no for me, too annoying. Can run both bosses and area MF spots with little fear of immunes. Considerably cheaper than Infinity (which is what MF is for, building wealth when you have none).
Man, has it even been a month since the last time this came up? No offense to the OP, but we debate this almost constantly.
Blizzard/Orb is great for Meph and Ancient tunnels (no cold immunes) but they are limited in the areas they can MF. They are also not gear intensive and end up being cheap to build.
Meteorb/Blizzballer/CL-FO are all great dual tree builds that can solo the entire game and effectively run every area in the game. These are also not really item dependant and are cheap to build.
LIghtning-Infinity is probably the highest damage casting sorc out there. With Infininty you can solo the entire game. This sorc is very item dependant and very expensive to build. Because the gear is also somewhat item specific they end up with a lower MF% than other builds. They compensate nicely by having a great killing speed.
It will probably come down to playing style and what you want/where you want to MF. My personal favorite is the Meteorb.