Cairo's most convenient districts for tourists are Downtown (near the museum), Zamalek (island in the Nile, quieter), and Giza (close to the pyramids). For a Nile view, hotels along the Corniche el Nile in Cairo have iconic settings. Budget guesthouses in Downtown Cairo start at $10-20/night.
Luxor's East Bank has most hotels near Karnak Temple and the main cruise ship terminals. Aswan is more relaxed — hotels on Elephantine Island offer peace and Nile views. Red Sea resorts (Hurghada, Sharm) operate on an all-inclusive resort model — book packages for the best value.