I have points in ANA, KrisFlyer, and Aeroplan! Is there anyway to consolidate them into one program, or transfer them somehow? What a mess! Should I just write them off and start over, using just 1 program?
Aeroplan miles can be transferred into ANA by several convoluted paths, losing well over 90% in the process.
If the amounts are small I would just write them off. If enough for an award then use them up. If almost enough for an award then consider whether its worthwhile crediting further flying or partner activity (or buying miles) to top up the account enough for an award - this may or may not be worthwhile depending on circumstances.
Which program is best depends on your travel patterns (where, how often and what class of travel), non flying activity (eg credit card) and what you want to get out of it (awards, upgrades, status benefits)?
Its generally best sticking with one airline alliance to maximise the benefits, unless you travel a lot.