Unless a TV uses a multiple of 24 Hz for its refresh rate, you won't be able to take true advantage of 24p. Also, just because a TV has a refresh rate that is a multiple of 24 Hz does not mean it will actually display 24p properly. For instance, there are many 120 Hz LCD TVs out there. However, a lot of them will not do 5:5 pulldown (where each frame is repeated five times so that the effective refresh rate is 24 Hz). Even if they will do 5:5 pulldown, you have to disable the motion processing feature to get it (this is the feature that most people think is 120 Hz, though it's actually frame interpolation).
If the TV doesn't offer something along the lines of 4:4 or 5:5 pulldown, then it's converting the 24 frames to 30 frames (3:2 pulldown).