Between a lotion and a gel, it's all about personal preference.
Lotions are a mixture of water and droplets of oil, ideal for very dry to dry combination skin types. Designed to absorb into the skin quickly due to its lower viscosity, so you can get on with your day.
Gels are water-based and completely oil-free, ideal for combination oily to oily skin types. May work well in hotter months, it liquefies on contact with the skin, dry and leaves a thin film of active medication.