Favorite anime films? I don't do many films, but among the ones I've watched, I've become a big Makoto Shinkai fan, so I guess pretty much anything by him. (To name a few: 5 Centimeters Per Second, The Garden of Words) Mamoru Hosoda has caught my attention in recent years as well, though. (Summer Wars, Wolf Children)
Favorite anime in general? As much as I hate trying to narrow down favorites, I've submitted to just blurting out Aria the Animation (and its following seasons) whenever asked. While I already enjoyed slice of life series beforehand, Aria really just... fully brought it out in me. Made me realize what exactly the slice of life genre was, why I enjoy it so much, and just that it is a thing and a thing that I should look for more of. And look for more of it I have done. But in the end, Aria still holds the top spot for me. Slice of life is a rather niche genre, so its appeal may not be widespread, but for anyone who enjoys it... well, frankly, I think most SoL fans are already aware of Aria, seeing as it's often considered the pinnacle of the genre. But if you don't know of it already, I highly recommend it. The series just has this magical ability to suck you out of reality and put you in a very relaxing, warm and fuzzy place.
If I had to give a top 5, then... Well, it might be a little dated by now, but I'll just give my top 5 from MyAnimeList:
(in no order of preference; just alphabetical)
- Aria the Animation (and following seasons)
- Death Note
- Eureka Seven
- Haibane Renmei
- Honey and Clover
...But really, the list could go on and on, for several different reasons. Especially with such significant differences in genres and such, it's too damn hard to narrow down a select few favorites, and especially so when it comes to recommendations. I really love a bunch of series out there, each for their own reasons.