Please tell me : which hotels in bangkok and pattaya?

For Bangkok, I recommend Centrepoint Silom. There were a lot of busted luxury condo projects from the Baht collapse in 1998 that got converted into hotels. Centrepoint Silom is one of them and it's a great deal for the price. It is adjacent to the Robinson shopping center, the Silom BTS stop (the public rail system), and it's a couple of blocks to the Chao Phraya River where you can catch a water taxi.