Gear is always a question I get, and gear is also something that I easily geek out about. I love finding out about new gadgets, new cameras, and new tools to make the work easier. However, the introduction of another piece of gear also inevitably creates another set of issues.
I shoot with a Canon 5D MKII for both stills and video. I always record on a dual-audio system: recording externally on a Marantz PMD620 and feeding that audio track into my camera using a Sescom LN2MIC-PMD620 attenuation cable (it is very important to use an attenuation cable to feed any audio signals into the 5D MKII so you don't overload the internal audio circuitry. The cable essentially lowers the audio signal by -25db.). I use a Rode VideoMicPro mounted in my hot shoe, fed into the right channel of a y-splitter cable. I then feed in the audio signal of a Sennheiser ew100 G1 wireless lavalier microphone into the left channel of the y-splitter cable. The y-splitter now sends the stereo signal into the mic input of the Marantz recorder. I will then set the recording level of my Marantz to fall between -12 and -6 db, and set my internal recording level of the 5D MKII to mimic the exact same levels as my audio recorder. This results in very clean audio in the recorder, and a clean audio signal to the camera. However, bear in mind that the audio signal of the 5D MKII will inevitably have more hiss than that of your external recorder given the internal circuitry of the camera. In post production, when necessary (eg. for clean interview audio), I will sync the audio track from the recorder with the footage from the camera using PluralEyes. I also use a Rode NTG-2 microphone to collect ambient audio when necessary (using the same Marantz recorder), and to boom my interviews. (see below for a list of links to the gear)
As far as rigging is concerned, there are many solutions out there, some more expensive than others. I have bought a couple of solutions over the past year, including the Jag35 DSLR cage, and a Cavision shoulder rig (the cheapest shoulder rig I could find on the market). I would recommend playing around with a variety of rigging solutions in order to find something that works for you. It all depends on the style of your shooting, and in most cases one solution will not be the end-all-be-all solution. Luckily, all support systems are standard across the industry, which allows for interchangeability of parts between systems. In my case, I've disassembled both of those rigs to create my own low-profile rig. I like to carry as little equipment with me as possible, and also prefer to shoot hand-held most of the time even though it yields less-than-steady results. I've come to embrace this style of shooting and have found ways to brace myself against walls or furniture to steady the camera. However, when I do require additional support during longer shoots, I break out my Cowboy Studios shoulder rig. For $30, this simple solution provides much needed support in a small package that clips right onto my belt. Finally, my workhorse lens is the Canon 24-105mm f/4L IS USM lens, which has image stabilization that provides additional stabilization necessary without the shoulder rig. I also use a Glidetrack LCDVF viewfinder, which adds an additional point of contact and stabilization of the camera.
Finally, I use the 755 XB Manfrotto tripod with a 701 HDV head, which is probably the best tripod ever made for video. The head is smooth as butter, but the greatest feature is the leveling head built into the tripod.
Camera: Canon 5D MKII
Lens: Canon 24-105mm f/4L IS USM
Audio Recorder: Marantz PMD620
Attenuation Sync Cable: Sescom LN2MIC-PMD620
On-camera Shotgun Mic: Rode VideoMic Pro
Shotgun Mic: Rode NTG-2
Y-splitter: Stereo to Mono Y-splitter cable
Wireless Lavalier: Sennheiser ew100 g1 wireless lav
LCD Viewfinder: Glidetrack LCDVF viewfinder
XLR-mini Stereo Cable: Sonic Studios XLR-mini cable
SUPPORT & RIGGING:
Video Tripod: 755 XB Manfrotto tripod with 701 HDV head
Shoulder Rig: Cavision RS1580S-SPE Shoulder pad with rod system, Cowboy Studios Shoulder Rig
DSLR Cage: Jag35 DSLR cage kit
Quick Release: Manfrotto 577 Rapid Connect Adapter