The best planet to visit apart from Earth in our solar system would be Mars. Mars is often considered the most Earth-like planet due to its relatively similar day-night cycle and the presence of water ice at its polar caps. It's a popular target for human exploration and potential colonization. There are ongoing missions and plans for future ones, like NASA's Perseverance rover and SpaceX's ambitious goals for crewed missions to Mars. However, it's important to note that Mars still poses many challenges, such as its harsh environment and lack of a breathable atmosphere, making it a complex destination for human exploration.