I have 3098 songs (approx 21GB) - 90% ripped at 256vbr via iTunes. I keep primarily complete albums (roughly 250 of them). I rate all of my songs as follows: 5 = love it, 4 = really like it, 3 = like it, 2 = don't really care for it, 1 = strongly dislike it. Out of the 3098 songs, I have roughly 500 5's and 1000 4's.
I use playlists to do most of my listening. I probably have 300 playlists, so I almost never use the artist/album/song menus. As examples of what I do with the playlists, I might re-order the songs on a greatest hits collection to put them in chronological sequence or omit a one-star song from an album (ex: revolution #9 omitted from white album).
I have a smart playlist that I call IPOD-FM which randomly selects 5-star songs that I have not heard recently, just in case I have no idea of what to listen to... I usually find an album within 2-3 songs from this playlist.
I also made an album (called "Singles") from 150 one-hit wonder songs that I mostly bought from iTunes. I made a few playlists from this group according to time period. There's a lot of 5's in that list as you might imagine since I specifically went looking for the song.
I am pretty anal about my playcounts also. I reset all of my playcounts about a year ago. I made a smart playlist called "never played" and worked it until it was empty. It took me a few months to get through the entire collection and in the process I weeded out a few albums that had all 3's or at best one 4-5 that got moved to the singles collection. My highest playcount is 5 or 6 - I tend to cycle through my collection one album or artist at a time rather than playing the same song on repeat (I never do that).
I love smart playlists. They are pretty useful for me since I am so anal about my tags, ratings, and playcounts. Sometimes, I will make a temporary playlist such as all songs by the Beatles rated 5 that I haven't played in the past 90 days (sort of my own greatest hits compilation).
This is probably WAY more information than you wanted but I like to talk about this subject.