Hotel Gardenias is a great place to stay if you're visiting La Paz on a budget, or if you want to avoid American tourists. Management was very accomodating of our 20-person group.
The atmosphere is currently a little faded-- you can see how the lobby and pool area were probably glamourous in the 70s. But they're renovating, so it could be snazzier in a few months.

Pros:
-clean
-nice pool
-quiet
-inexpensive

Cons:
- noisy air conditioner
- a little far from town, albeit walkable and fine with a car
- very basic amenities

We spent three nights at Las Gardenias, and I have to admit it was a bit rustic for me. The rooms were simply furnised, but clean. The beds, though, were terrible and the A/C unit was horribly loud. Speaking of loud, we came at the end of Holy week, and this is a big vacation time for the locals, who are the primary clientel of this hotel. The place is made out of concrete walls and block so it's pretty noisey and a bunch of celebrating locals made it more so at night.
It might sound like I'm really down on this place, but I'm not. For less than $50 per night, it's a bargain- I just wouldn't stay there near Easter.
What I do highly recommend is La Paz in general. This feels a lot more like true Mexico than Cabo. There's few American tourists here- after a few days in Cabo, you'll know why that's a good thing, The locals are very kind, there's a great selection of good restaurants, shopping is great (don't miss nearby Iberra's pottery), and the scenery if awesome. Sunset on the malecon ( the local boardwalk) is an experience not to be missed!
All-in-all, there are probably better choices to stay in La Paz for those that prefer a more refined experience, but the city itself is a treasure and a wonderful place to explore.

I chose Hotel Gardenias because its bilingual staff could communicate with my Sesame Street Spanish. For $34 USD, I got a room with two full beds, television (which I never turned on), private bathroom, and free access to the beautiful pool.
For under $5 USD, I got a "Continental" style breakfast, including juice and coffee. The hotel had simple maps available, and arranged for my taxi to the airport before I had checked out. They also had several paperbacks (in English) for the taking.
The bedroom floor was tiled, not carpeted. I actually liked this more than I thought because I believe it was easier for the house staff to clean.
Because the bed linens were mended, I noted that they had been changed daily. (I've marked sheets in more expensive hotels and not had them changed.)
The only thing that kept this from a perfect review is that the hotel does not offer internet access (at the time of this writing, summer 2005).
The staff made itself available to us, and they were very nice. I was in Mexico for what amounts to a body modification convention. Unlike what I've experienced in the States, I was met with some curiosity but with no rudeness. I would probably consider a car next time, since I got lost in town before I got my map (and I have the blisters to prove it) and Hotel Gardenias is not on the Strip. However, I would certainly consider Hotel Gardenias upon my next visit to La Paz.

Hotel Gardenias is about 4 blocks off the Beach, so it is considered a "Mexican Tourist" hotel. It is a well maintained typical architecture hotel; a central swimming pool surrounded by two stories of rooms. It has a secure fenced parking lot. I elect to stay here, but if you want to be in on the action and on the Malecon when you step out of your hotel, go to the La Perla or Los Arcos. Just don't take the rooms closely overlooking the street. The younger crowd of La Paz cruise the Malecon every weedend - very noisy. Hotel Gardenias is ..... ahh ......
quiet.