That's a hard question to answer.
If I'm not keeping up with the series, then usually I just go with my favorite group. But if that group I like gets too far behind I get worried. So when that happens I might get another group's fansubs and replace it later with the group I like.
If I'm keeping up with the series, then I usually get the first one that comes out and replace them with the one I like. Unless the group I like was the one that I got first.
Out of the last sixteen series I viewed:
1. Six times - I went with my favorite group's fansubs, but theirs came out only 2-6 hours after the first groups. So it was very easy for me to wait.
2. Five times - I got the first groups, but later replaced them with my favorite group's fansub.
3. Three times - I got it from the group because they were the only group doing the series.
4. Once - I only went with my favorite group even though their fansub came out significantly after another group(s).
5. Once - I went with a group because they were always several episodes ahead of everyone else.
I guess I'm more of a "first" person than a "favorite" person. But I often get with my favorite group's too so it's hard for me to answer for sure.
