The power packs are interchangeable, as are the AV cables. The video standards, however, are not. PAL TVs generally support NTSC as well, NTSC TVs never support PAL.
None of the TVs in my house support PAL, not officially anyway. I can confirm my 27" CRT will NOT do PAL, never tried the 46" LCD. Maybe I just got unlucky, or maybe it depends on brand.