My wife and I spent a week in Mazatlán for her birthday (February 28 - March 6) and we had the opportunity to stay at a variety of hotels. We stayed at Hotel La Siesta first, then Hotel Playa Mazatlán, and finally Hotel Lerma. The price ranged from expensive (Hotel Playa Mazatlán), moderate (Hotel La Siesta), and cheap (Hotel Lerma). Out of the three our favorite hotel was Lerma and that's saying A LOT! Because we liked all three hotels for different reasons.
Hotel La Siesta is a good value and lots of tourist stay there, it's right in front the beach (Playa Olas Altas) and the malecón and right around the corner from the historic zone in old Mazatlán. Hotel Playa Mazatlán is in the Golden Zone aka tourist zone and in my opinion it's the best value out of the large-resort-type hotels if that's what you seek. It has a nice private beach (Playa Las Gaviotas) right in front of it and is right next door to some of Mazatlán's most popular clubs & bars. Joe's Oyster bar is a rock throw away.
Hotel Lerma is a few steps away from Playa Norte beach. It's a 5 minute walk max. It's less "touristy" but they still receive a fair amount of foreigners. We saw quite a few while staying there but nowhere near the level we saw at the other hotels. The staff and management is very friendly and they keep the place spotless. Security is good and there is a ton of parking and best of all it only cost $12 a night for a double bed with private bath and fan! What won us over beside all of the stuff I just mentioned was the place had a homey authentic Mexican feel. It was reminiscent of a room in Havana, Cuba. It has huge windows that open up to the street activity below (we stayed on the 2nd floor), but it was never loud or noisy. The street is very quiet and during the day when you open up the windows and turn the fan on you could just sleep for hours in the comfortable beds, which we did several days in a row, the room is very breezy and makes you relaxed & lazy. Or you could watch the activity down below on the street.
I would definitely stay at the Lerma again and I highly recommend it for people who are just looking for a nice place to rest their head, cheap, clean accommodations that are authentic and close to the beach. The authentic, non-hustle and bustle feel of the place is what puts it above the rest for us. At Hotel La Siesta there was a guy in the lobby constantly trying to sell us time shares and get us to go to this one resort in the Golden Zone and the staff didn't seem to mind him being there. Lerma didn't have none of that riff-raff. You could just come and go as you please and relax. It's VERY comfortable & cozy. Check it out!