How long can you be gone? If you're able to swing a 14+ day tour, I would pick a longer one if I was triaging choices, even if it is to a country you've been to before (e.g., Italy). If you're physically able, I'd also suggest picking a more strenuous tour over an easier one or one that requires a bit more travel time. For example I did the Best of Turkey in late September, early October. It was a very long slog from west coast USA and some tour days were pretty strenuous. But wonderful culture, food, and weather was the reward in spades.
Still can't decide? Put the tour options that suit your dates in a jar, pick one, and leave the rest for the next time.