Triangle Heart was really good. Much better than most martial arts oriented anime out there.
When I first saw Nanoha, with a ordinary girl suddenly becoming a mahou shoujo, with a magical staff, a little mascot and having to retrieve lost magical items... "wait.. Is it you, Sakura?!" Contrary to my expectations, the series developed VERY good, like Triangle Heart, there is nothing else to compare it to other mahou shoujo series. Things happened so fast. In just 13 episodes, it was like watching a normal mahou shoujo in Fast Forward mode.
Now on A's, the first scene was a magical book that suddenly broke its seal... "Right, the Clow Book... it was missing on the first season...". Again, it surpassed my expectations. The first two episodes were very dense. For some time I was desapointed, because it looked a little like a DBZ fighting scene... but the end of episode 2 changed everything again. It's overwhelming.