YMMV of course. I liked Morgana's journey into evil in series two while most of the fandom didn't. I hated her in series three though. The Arthur/Gwen episodes were boring and didn't make much sense, the Gaius-centric eps were boring as fuck as well as pointless and the lack of magic reveal pisses me off like you wouldn't believe.

There are some great stuff thoug! Morgause is badass and awesome, Cenred is hot, the Slash Dragon is a bitch and Gwaine is pure love.

The next parragraph's really spoilery, be warned.

The scene in which Merlin poisons Morgana is one of the best things I've seen. Arthur finds out about his birth and tries to kill Uther (and then they hit the reset button on that one). We see Ygraine and Merlin's dad, the round table, the Lady of the Lake and Excalibur and Gwaind. Just Gwaine.