To be sincere, both are very good in what they offers and thus I think it might be hard pointing out which is better or not, also to add, both are still developing their ecosystem thus still have a long way to go.
But currently Solana is already making huge moves which has seen the price create another ATH, not only that, Solana have a way of supporting good projects on its blockchain such that the more they grow and develop, the more Solana grows as well, hence one of the reasons that a growth in Solana pulls other coins along.
Polygon is also making huge impact but Solana seems to be a bit ahead of it, Polygon can also be seen to be contending with Binance Smart Chain since some projects are already migrating to it, therefore the more projects migrates to it, the more it grows.
However, if I am to choose one from them, I would go for Solana.