I have some friends who have toured the US and enjoyed that.
Also, had some friends who have taken cruises.
Neither is really my thing, instead I much enjoyed Paris, Berlin, and London. Agadir, Morocco was also fun and not TERRIBLY expensive. Gibraltar on paper seemed to be an affordable week-long vacation though it was ~6 months last time I looked at my travel plans for there.
I haven't been to Moscow yet but I'd always love to go. Keep in mind during your planning stages there are TONS of places out there and even a 3 day vacation to somewhere like Paris is fantastic.
Wherever you go, fair travels and have much fun. And remember, be excellent to each other.