For MIP and LP I have used CPLEX, Gurobi and to a lesser extent Cbc. I used those three using JuMP (Julia package for mathematical programming) and Gurobi via pulp and pyomo. Of all three, I think Gurobi has a very accessible documentation, note that I am not saying better or more complete which in that case it would go to CPLEX, and the integration with Python straight out of the box is very useful. Cbc is a lifesaver when we couldn't access the academic licenses of the other two. Overall, I think CPLEX/Gurobi are my favorites with a slight edge to Gurobi. I have tried formulating problems using .lp and GAMS but JuMP is so much more ergonomic even if it's strictly tied to Julia (which I find to be a good thing).