I really love 4-5, but only because I can abuse all those summons and get quite a few units to max levels.
@Ninji: Tibarn is yellow on the bridge map, isn't he? You should be able to stop him from stealing your kills.
And I like 3-E because of the foreboding feel it has. The heartbeats, the music, and the whole situation surrounding the battle (the medallion going crazy) gives it a pretty tense feeling, even if the battle itself is pretty easy (unless you have a Dawn Brigade unit at tier 3 like I did with Aran once; he almost killed Ike when he activated Impale).
Also, my first play through took 40+ hours. I wasn't drained at all, even though I thought it was really long compared to the other FE games I've played (~20 for FE7, 8 and 9). I immediately started a new game after I finished, beat that new game sometime later, and then immediately started another new game (which I have yet to beat due to complications but I am close to).