I think this is a good question for a topic.
Personally the reports I enjoy reading the most are those on aircraft/carriers I have either travelled on or even better am booked in the future on to get an idea of what to expect e.g. I'll be flying EK
for the first time in september so have been reading a lot of EK
reports recently. There are lots of different styles and none is superior. I do enjoy longer reports as long as they are split into distinct sections or well paragraphed so I can skip certain bits if maybe they don't interest me but as much information as possible is good in general. A very simple tip is when you have finished read it to iron out any obvious errors.
What I don't like is when people advertise their trip report with pictures and then just link to a few photos from the database taken by somebody else on a different day. I tend to link to a few of these just for context but like to include my own which would probably never be good enough to be accepted onto the site. I like cabin shots and any pics that give a feeling for the journey, although too many photos can (IMO) ruin a trip report, especially if they are just endless pics of clouds. The most frustrating thing is when you come to a report which interests you with some potentially good pics and you get those damn "bandwidth exceeded" messages. If you are going to post photos plan for lots of people to view them as if they disapear after a day then I'd rather they weren't there at all.
Finally what makes a good trip report for me is when people take the time to comment on people's work. I think if you read it and enjoy it you should leave a note, even if its just to say great report, as a lot of work goes into the reports on this forum which can seem to be under appreciated, especially as it often of a very high quality. I've taken loads of trips over the past few years and written the odd trip report. These have taken me a long time to do and often drop off the end of the page after a week or two, so generally I don't bother any more unless something amazing happens that I simply must tell people about.
P.s. Well done, we got to reply 12 before we got our first plug! Seeing as everybody is now doing it this is what I think a good trip report should look like