In a high-rise overlooking the Malecón [1], Casa de Rene Pérez (Malecón #51, e/ Tenios y Carcel, tel. 07/861-8108, rmichelpd [at] yahoo [dot] com, CUC40) is an unusually lavish option with two spacious and windowless yet romantic rooms decorated with antiques. They share a mediocre hot-water bathroom. The vast lounge is sumptuously appointed and has a TV/VCR plus views along the Malecón. Entry is to the rear, via the parking lot.
I also recommend Casa de Elsa y Julio Roque (Consulado #162, Apto. 2, e/ Colón y Trocadero, tel. 07/861-8027, julioroq [at] yahoo [dot] com, CUC20, CUC25 with fridge and TV), with a pleasant lounge with leather sofas. Run by erudite and delightful owners, it has two rooms with fans, wicker furniture, and modern bathrooms, and each has an independent entrance.
Hostal el Parador Numantino (Consulado #223, e/ Ánimas y Trocadero, tel. 07/863-8733, CUC30) is a contemporary conversion with a spacious lounge with gleaming ceramic floor and comfy leather sofas. The two bedrooms upstairs are small and feature fans, TV, and mini-fridge.
La Casa Colonial (Gervasio #216, e/ Concordia y Virtudes, tel. 07/862-7109, CUC25) is a gracious place with two spacious and pleasantly furnished bedrooms with fans, and filled with antiques. It has a nice courtyard.
Other room rentals nearby include Casa Colonial La Terraza (Calle Belascoain #207, e/ Concordia y Neptuno, tel. 07/864-1275, www.casaterraza.com [2], CUC20–25).
Links:
[1] http://www.moon.com/destinations/cuba/havana/sights-centro-habana/the-malecon
[2] http://www.casaterraza.com