for me atm star strike blast and the duelist revolution are amazing packs... deltafly is an awesome lv3 dragon type in the duelist genesis, star strike also has a load or really nice looking cards with decent or balnced effects.. (makes up for the shining darkness) dragunity drive is also looking to be something special. dragons finally get a new field spell with a decent effect (once per turn u can activate one of the following effects 1. add 1 lv4 or lower dragunity monster from yoyr deck to your hand. 2. send 1 dragon type monster from your deck to the graveyard.)
previous sets i thought OMG to are invasion of chaos, magicians force, stardust overdrive... there are others but ill be rambling again...