As long as you first understand that you will only get others views, i.e. their options. I truly don't believe one T3 is better than the others.
However, if I was strapped to a chair, had a car battery attached to my nipples and was forced to produce an answer, I'd say go for the Tengu. I don't personally fly it, but it seems to be the most widely used across the board. Much like the Drake (in a general sense, not that it really is like a Drake), it fills a variety of roles very well, has a solid tank, and missiles are easy to use with low SP (don't get me wrong, like all things, they require a lot to use effectively).
They have been used for level 4 missions, I see them all the time in my WH, and, prior to moving into said WH, they were a common feature in 0.0. They are a good all around T3. Look on youtube for the 4x Tengus running C6 sleeper sites.
I would also say the Loki and Proteus are well liked and used often, the Loki probably a bit more so than the Proteus, but both are solid PvP boats. The Legion I see used quite a bit less than others, I'm not sure why.
Again, this is all based on observations and opinions of my own and nothing substantial, but you wanted peoples views, so there you have it.
Also, what CanHasGank said