There are several things you need to think about when choosing which mics you want for your audio-for-video kit. Will you primarily be working for local indie film makers, or looking to be "the" one to call for out-of-town producers coming in to shoot news, news magazines, corporate videos, etc.? The Sennheiser 416 has been the standard in the industry for a long time. If an out-of-town client calls and requests what gear you use, they will almost certainly recognize that model. That said, the NTG-3 has received great reviews and many compare it favorably to the 416, and it costs less. Your local indie friends won't care about the name recognition. Both of those mics are excellent choices from a sound quality perspective. You might also look at the Sanken CS3-e. I have not personally used it, but it is building a very strong reputation. I would not go with the Sennheiser ME66. You might as well spend a little more and get a MUCH better mic.

You also need to consider some sort of hypercardioid mic to use for dialog in interior, reverberant spaces. The 416 is a pretty good all-purpose mic, but if you are inside in a space like a kitchen with tile floors, or a dining room with oak wood floors, or even just low ceilings, etc., then your best bet is to use a hypercardioid mic. The standard in the biz is the Schoeps MK641, but that will set you back about $2000. Lower cost alternatives would be the AKG SE300 mic with the CK93 capsule, or the Audio-Technica 4053.

Then there are wireless systems with lav mics, and wind protection, and handheld interview mics, and headphones, and a great mixer...

Have fun!

Rob

Although the self-noise levels of the NTG-3 and the MKH-416 are specified as being the same, the Rode has nearly 6dB greater sensitivity than the Sennheiser. This will help when using them with a relatively noisy recorder such as the H4N, especially when the recorder is supplying the phantom power.

On the other hand, the MKH-416 draws only 40% of the phantom current of the NTG-3, so would enable longer recording sessions if powering from the H4N internal battery.

You may find the H4N does not have enough gain for either mic on distance shots, even before you take the recorder's input noise into account. An external battery-powered pre-amp (such as a Sound Devices MP-1) placed between the microphone and the H4N would give you greater gain with much lower noise, coupled with greater flexibility and ease of level adjustment when recording under difficult conditions.

Thanks guys I really appreciate the help and advice.

The 416 has been the industry standard for a long time. If money is not an issue then you should probably try and have one of them as much for the reassurance of the "name" when mentioned to clients, as for the mic itself. Having said that, the NTG-3 seems to get great reviews. I listened a while back to some comparison clips on youtube where the Rode compared well with the MKH416. I know youtube is not the best for making critical sound judgements, but I would think really there is not too much between them in terms of sound. I haven't actually tried the Rode myself yet though. If anything I would think adding a top quality low noise preamp rather than using the Zoom pre's would make more of a difference to the overall results than the choice between the two mics here.