Before all of the bickering begins, always seems to happen... Code this vs code that...
I'll tell you what i've learned from the guys on here. I'm no expert though. Find an online calculator to determine voltage drop with the wire that you pick. I am using 2-2-2-4 MHF but my run is under 200ft total. I've been told that it won't do 100 amps, maybe 90 max. I only plan to add a 60 amp breaker anyways so that works for me. MHF can be direct buried but has to be in conduit in the house, SER can't be in conduit or direct buried so i've been told. My plan is to use SER in the house, splice in a junction box at the basement wall and run MHF in 2" conduit to the barn. Out there will be another 100 amp panel which will serve as a disconnect with other circuit breakers for my lights, compressor, outlets etc... At only $1.45 a foot at Home Depot this seems to be the cheapest route I could find. I'm also running a 1" gas line and 1" conduit for cable, internet and phone. Calculate what your "actual" max amperage needs to be since that will dictate the size wire and cost...