It is difficult to determine which cinema in Chongqing IMAX is the best, because it depends on one's viewing experience and preferences. However, according to the information provided and comments from other users, the following are some theaters that may provide excellent IMAX effects:

1. Stellar International Cinema (Jie Fangbei IMAX Store).

2. Dolby Cinema (wanda plaza in Nan 'an District).

3. Jinyi Studios (IMAX Store of Starlight Plaza in Nan 'an District).

4. Lumiere Cinema (chongqing heaven and earth Store).

Please note that the IMAX screen size and projection technology of these theaters may be different, so it is recommended to compare them according to your own needs and preferences when choosing the viewing location. In addition, the Science and Technology Museum and Wanda Studios also have good IMAX screen and projection technology, but they can't provide more information because they don't specifically mention which theater.