Almost always reliable for a value-priced bed in the middle of the action, the Assembly is a secret that scrimping millennials won’t want to share. Rooms are wee and sparse, to be sure, but they’re modern (blonde wood, charcoal carpet, and subway-like tile in their little bathrooms) and clean, and because the Assembly inhabits a tower practically on top of the National Portrait Gallery, many of them have sublime views of the city. You won’t get a phone, a desk, or even a lobby to speak of, but do you really need those? To compensate for the lack of TVs, the Wi-Fi is perfect, whip-quick, and free. You get a leafy rooftop bar/restaurant with a splendid east- and south-facing panorama that you won’t find at luxury hotels five times the price. The evening pursuits of the West End are at your feet and the low price point creates some inevitable churn in the guest list. The very cheapest units might not have a window (you’ll be warned), so pay another £20 to bump up with 30% more space; most rooms sleep 2 but “suite” rooms accept 3. Book direct for 10% off. Really, this is a crash pad extraordinaire.