North of the river, well-regarded Hotel Rondó (1 Norte 157, tel./fax 0322/977157, www.hotelrondo.cl [1], US$45/55 with breakfast) is good value for the price. The 
Magno Hotel (Arlegui 372, tel. 0322/713816, www.magnohotel.cl [2], US$77 d) is a beautifully modernized downtown hotel.
A couple blocks west of the Rondó, Hotel Monterilla (2 Norte 65, tel. 0322/976950, www.monterilla.cl [3], US$66/83 s/d) is a cozy (19-room) hotel across from the casino and easy walking distance to the beach and several good restaurants. Hotel Marina del Rey (Ecuador 299, tel. 0322/383000, fax 0322/383001, www.marinadelrey.cl [4], US$100 s or d) is a Best Western chain affiliate.
Links:
[1] http://www.hotelrondo.cl
[2] http://www.magnohotel.cl
[3] http://www.monterilla.cl
[4] http://www.marinadelrey.cl