By a large margin, I'd go for Last Exile #1. It reminds me of Star Wars; epic fantasy setting, exciting aerial dog fights and very realistic, down to Earth personalities.
Kiddy Grade #5 is the best volume of the series so far, but something about this show just turns me off.
Same applies to Love Hina #4- very impressive and fun set of episodes within the confines of the series' zany formula, especially after the mediocre previous volume.
Gad Guard #1 I haven't seen yet, but I have been hearing that Get Backers is a good series (though it's 64 episodes?).