I look for consistency between tests. You want repeatable results that will highlight small changes in fitness. If the Allen/Coggan method looks attractive, then use that. It really is just a matter of picking one and seeing how it fits for you. Your first FTP test is pretty meaningless in the grand scheme of things.

That said:

• My favorite overall is the MAP test (ramp test), because it is very sensitive to fitness changes, and my zones always feel perfect when based on a MAP number. What I don't come out with is an FTP number -- I just have to go with a % of MAP. Again, this is a great number for training.
• My second favorite method is a fully-recovered 20-minute test. This really doesn't provide a direct FTP, and everyone will be a different %. I can still subtract a %, and train on zones from that number just fine. The advantage of this test is that I feel like I should be kicking ass. Like a TT -- very motivating, and that's good for my consistency.
• The other test I've done that deserves mention is the all-out 3' CP test (you can search for it if interested). This one has the advantage that the number you're looking at for the last 30 seconds is your CP (so really close to FTP, and easy to convert accurately). So this is possibly the most accurate FTP test I've done, it only takes 3 minutes, and it doesn't wreck your training day or your week. The bad thing is that it is the most painful thing I've done on the bike, including crashing. There's this point shortly after 2 minutes where everything stops hurting, and you can just go at 100% every pedal stroke like it's determined by a dial. Getting to that point is bad news though.