Hotel Monte Igueldo DOES have fantastic views, 360º-views. I was UP THERE just last year and wow... it's just amazing and great sunsets too. BUT look, I'm not sure what time of year you'll be there but if it's in the summer you'll have good light until almost 10pm but you may not return from dinner in the city until AFTER 10pm (at least I HOPE you don't eat and finish before 10pm!
) and you'll have no view from the hotel unless there's a moon. But waking up in the morning.. wow.. that must be amazing. The hotel itself is not "all that" but is nice. The location is the best thing about it. Okay, I didn't go inside but it's not very attractive from the outside. The tower next to the hotel is a definite must for fun and even better views. You can also take the "funicular" up/down Monte Igueldo but it'll likely be shut down by the time you return to the hotel at night.
Regarding
Hotel Londres , I think we've had some reviews on that one already. Try a search to find it/them. This one is RIGHT on the beach as you see from their website. This one also has a nice bay-view and is a nice, walkable distance to pedestrian "La Parte Vieja" (the Old Part) along the seaside "boardwalk" (no boards, just cement and railings). By the way, don't be surprised to see nude sunbathing on the beach.
:p
I couldn't find a website for Hotel Inglaterra, though, so I don't know anything about this place.
Wow, you are SO going to love San Sebastián - SUCH an elegant city. I envy you.
Saludos, MadridMan