Beautiful hotel, but the Dawin is more convenient and also nice on the upper rooms.

When I went to Landmark hotel in February, they finished renovation, and the lifts now require key cards. I picked landmark before because 1) it was luxurious 2) it didn't require key card so the LBs and GGs can come to my room easily. I had to pick them up which was annoying. Next time I'm in Bangkok, which is next month, I will be looking for something without key card access. Any advice would be appreciated. I only stay in luxury hotels.

Thanks to you both. Already quite a few to chose from so I will go and search the best deals. Looking forward to the trip...........    

I agree with everything written by. @Unavowed.   All those hotels are very good to excellent and will be perfect for a mongering.   If you are interested in considering other luxury hotels similar to the Standard then it might be worth also looking at the options available just one BTS stop away from Nana in Ploen Chit. This would include the Rosewood (outstanding hotel), Park Hyatt and Athenee. However if the main focus of your trip is to enjoy the naughty nightlife and have some LB action you will struggle beat the Hyatt or Sofitel, so convenient and high quality.   One more thing to note if you are looking in that price range is that the Landmark (the old high quality mongering classic option) isn't really up to the standard of the Hyatt or Sofitel these days. A group of friends who stayed there recently were quite disappointed despite having fond memories of previous stays there.

I don't know much about Grande Centre Point hotels, but can comment on the other hotels you've mentioned. The Grand Hyatt fits the bill for R&R without being too far from the action and is in a very nice area. I didn't bring back any guests when I stayed there but you would have no problem or judgement if you did.Both the Hyatt Regency and Sofitel are excellent hotels that are almost next door with all the facilities you need, but Sukhumvit can be chaotic although very close to the main LB bars. Mercure is a solid choice for the convenience of Soi 11 but it's a distinct step down in terms of quality. I'm sure others can comment on whether Gande Centre Point is a good place to stay but from my experience the Grand Hyatt, Hyatt Regency and Sofitel can give you R&R and convenience. There are plenty of YouTube reviews on all of the hotels to help make your choice.