I just watched all 4 Halloweentown movies and I noticed a few neat things I hadn't noticed before, 1 was a negative though.
1) Debbie Reynolds as the Aggie Cromwell is one of the most magical Disney characters ever (besides the fact that she is a which). I rank her up there with Mary Poppins
2) Lucas Grabeel (my favorite actor from HSM) was in Halloweentown High as well as Return to Halloweentown, and Oleysa Rulin (who played my favorite character in HSM) was also in Halloweentown High
3) Very interesting stories all around
Now the negative - Return to Halloweentown, pretty much everything about it. Debbie Reynolds basically just phoned in this movie (she had what 10 minutes of screen time?) and she is the most interesting character in the series. The youngest of the kids wasn't in it at all, just mentioned here and there. And by far the worst thing about Return to Halloweentown.... Sara Paxton replacing Kimberly J Brown as Marnie Cromwell Piper. Apart from that, the 4th movie felt altogether cheesy compared to the previous movies, the visual effects, while good, were done to too much of an extreme, it was almost as if they just wanted to do a Halloween movie and show off the special effects. A lot of the magic from the 1st 3 movies was achieved through puppetry, and animatronics, not cheesy computer effects.