From what I can see now, Trump has indicated he will request a recount in Wisconsin. It is worth noting, unless noted, states require the campaign requesting the recount to pay the costs of the recount -- though they are "forgiven" or refunded if the winner of the election changes or (depending on state) if there is a "substantial" change in the vote count.
Michigan: It appears that the only way a recount can be requested in Michigan is if the Trump campaign alleges that some specific act of fraud or mistake, and that will only cause a recount in the precincts where the fault is alleged.
Arizona: Arizona will trigger an automatic recount if the vote count ends closer than 0.1% (one-tenth of one percent). There is no way to request a recount.
Nevada: It appears there are no requirements to request a recount, either side can request one -- in fact, it appears that any Nevada voter can request a recount.
Georgia: A recount can be requested if the vote ends up with a margin of 0.5% or less. Additionally, it appears Georgia is one of the few states that pays for the recount.
North Carolina: There is an automatic recount if an "error" is found by the state during the count. Additionally, the campaigns can request a recount if the vote total is less than 1%. North Carolina is another state where campaigns are not charged for requesting a recount.
Pennsylvania: If the margin is less than 0.5% there is an automatic recount. Otherwise, recounts can be requested with no requirements.
It will be interesting to see if any automatic recounts are triggered. Trump's campaign has said they will request a recount in Wisconsin, and I'm guessing they'll allege "irregularities" in Michigan to have a recount, with the only question is how much of the state they'll request recounts in. I also suspect if Trump ends Pennsylvania that they will request the recount.
Any guesses as to what other states recounts will be requested in?