Australian-run Los Dos Soles (Miramar 66, tel. 072/841546, windsurf [at] terra [dot] cl, US$5 pp–US$12 pp) is a surfer hangout with hostel-style accommodations and some private rooms.
Residencial Antumalal (Aguirre 64, tel. 072/841004, antumalal [at] costapichilemu [dot] cl, US$10 pp with private bath and cable TV) is a friendly family-run place with plain but comfortable rooms surrounding a shady central patio.
At surfer-friendly Hotel Chile España (Av. Ortúzar 255, tel./fax 072/841270, www.chileespana.cl [1], US$15–19 pp), rates vary according to whether the room has a private bath, but all include breakfast. Some ground-floor rooms, though, are dark.
Under the same management, down the block toward the seashore, everything works at well-worn Hotel Rex (Av. Ortúzar 34, tel. 072/841003, US$19 pp); its fish/seafood restaurant, though, is more appealing than its accommodations.
Some rooms at moribund Hotel Asthur (Av. Ortúzar 540, tel. 072/841072, www.hotelasthur.cl [2], US$40 pp with full board) are dark, but it does have a restaurant and a pool with a view.
El Balaustro (Av. Ortúzar 289, tel. 072/ 842369) is a pub/restaurant that serves both beef and seafood.
Links:
[1] http://www.chileespana.cl
[2] http://www.hotelasthur.cl