I'm French, from Paris, 33 years old and a branch of my family is Romanian.
During summer 2008 I decided to have my holidays at the black sea. A friend of mine who never been in Romania came with me, so I had the responsability of the choice of the Hotel at the Mamaia resort.
Hotel PALAS was a very good choice.
Holidays in Mamaia are very amuzing and a funy if you follow simple advices.
For comfort, avoid the big hotels of the south part of the station. Go rather in the nothern part of Mamaia. Hotels are smallers with a level of service comparable to western europe. Hotel Palas belongs to a known romanian business man, he invested in it.
So rooms are very nice. It's not noisy, you can sleep the window open eventhough each room has airclimate. It's very clean, and the breakfast is good (better to have it before rush hours).
Beach is at 30meters.
Book the room with a romanian travel agency on internet. It's half less expensive. 70€/night versus 140€ at desk.