The obvious answer is the pool with the highest APR. But that is not the only reason to pick a certain pool. Currently the highest APR is OSMO/DVPN pool at 205% APR as of today. This pool has been very resilient compared to all the other pools and the APR has stayed above 200% almost the entire time since Osmosis launched. I have seen other pools have a higher APR at some point but now dropped way lower than 200%. In addition to the high APR I have also observed that the price of OSMO and DVPN have been very closely matched, both moving up and down together almost exactly the same percentage (see price chart below). When the pairing moves together this reduces the amount of impermanent losses. This is a good pairing for LP in my opinion. Both of these tokens have huge growth potential as well. Right now both tokens are down ~36% in the past month and IMO it is a good time to put more into this pool.