1. Casting Liam Neeson and Qui-Gon's character
2.The Soundtrack
3. Saber duels, in the desert and in the palace.
4. Outstanding CGI
5. Casting Ian McGregor as Obi-Wan, I can make the reach with him as a young Obi-Wan.
6. Palpatine/Sidious were handled well.
Didn't like:
1. Casting of Lloyd, too young for the part..basically alot wrong with the character, should have been more like a young James Dean, Amidala would have been uptight, but secretly attracted to Anakin's as a bad boy (mirrors Liea/Han in a way)...The age difference gives it a strange babysitter infatuation thing.
2. Anakin making 3PO, I'd flip it around and have the Queen own the protocol droid, and Anakin makes R2, makes more sense and mirrors the OT better (Leia 3PO, Luke R2).
3. Jar Jar or the Gungans, There were enough things going on at the end of the movie (Anakin and R2 blowing up the control ship, Amidala taking back the palace and the saber fight,Gungans and Jar Jar were never needed.
4.Trade Federation, Didn't like the look or sound of them, Would have preferred using Mandelore army for the invasion, Sidious would bribe the commander with a clone of his own (which becomes Boba Fett) and or a lot of clones of himself to command..Battle droid's also didn't appeal to me.
5. Yoda was a puppet not CGI which I liked, unfortunately he didn't look enough like the OT puppet (when you're already 800-900 years old, 30 or so yrs between episode I and IV isn't going to change his apperance that much).
6. Obi-Wan's character, I thought he should have been a stronger character,sent as Amidala's protector, a Jedi Knight and Yoda's apprentice, not Qui-Gon's who they should have turned into Anakin's father who left the Jedi order.
7. The Padawan hair style, the braid and samurai ponytail thing just irritates me, would have been sufficient to just give them a buzz cut.
8. Name selection: Padawan,Naboo, Shmi...Dooku, sounds like baby talk.
There are more good and bad things but these are the obvious ones, I'll think of some with Clones.