Audio
Audio quality makes a massive difference to the quality and watchability of your films. Whether it's dialogue, music or sound effects, the audio of your films can make or break them. MAGIX I music maker is a sophisticated music tool with a professional range of functions for detailed arranging and editing, straightforward remixing and flawless CD mastering. It now provides fully-professional sound quality while retaining the renowned simplicity of its user interface from the creative spark all the way to the finished CD. With support for real-time DirectX effects, DXi and ReWire software synths, MIDI FX plug-ins, and ACID-format audio loop technology, Home Studio takes your music farther, faster, and for less money than any comparable software product
Here are some programs that will help you add good quality audio to your machinima. If you need music to add to your films, you may use that of Aware, an experimental music co-operative.
Audacity - Audacity is a multi-track audio editor. It's an open source project, free to download and use. It's really intuitive and easy to use, unlike a lot of music programs. You can record your dialogue and get the levels right with the amplify effect. There are loads of different effects you can use, like changing the pitch or tempo so you can act out male or female roles. You can add echo and delay or play things backwards, great for spooky films. And loads more. You can also use it as a music editor for background and atmospheric music. Versions for Windows, Mac and Linux. 
Tuareg (TU2) - Tuareg is an excellent music creation program, free to download and use. It includes a drum machine and sequencer. If you register the product (and pay) you get a sampler and a synthesiser. It's dead easy to use, and you can build up whole tracks to use in your films, or just create weird sound effects. There are some pre-defined drum sounds, or you can import WAVs and play around with those.
Music Maker - MAGIX is celebrating music maker's 10th birthday. The anniversary version is being released with numerous new features that simplify the music making process.
Adobe Audition 1.5 - Designed for audio and video professionals in studios, broadcast facilities, and post-production houses, Adobe Audition software offers a powerful, flexible, and well-integrated set of tools for advanced audio mixing, editing, mastering, and effects processing. With Adobe Audition, you can create superior quality audio easily and efficiently as you mix up to 128 tracks (including as many as 32 live inputs), edit individual audio files, create and use loops, and apply more than 50 DSP (digital signal processing) effects, filters, and audio restoration tools.
Cakewalk Home Studio 2004 - You don’t have to depend on anyone else to get your music recorded. Do it all from your PC with Cakewalk Home Studio 2004. There is no better Windows software available for musicians taking the step into the world of digital recording. Home Studio provides you with everything you need to turn your PC into a powerful multitrack recording studio.
Magix Sound Essentials - sound effects (4,200 sounds). Gigantic selection! 4,000 impressive royalty-free sounds for any montages! Includes 200 atmospheric background music pieces. All on 1 DVD-ROM! Plus impressive sound effects and much more. Never again annoying crackling, disturbing noises & embarrassing silences! MAGIX Sound Essentials Volume 1 for Video & Photoshows 2004 is ideal as a compliment to MAGIX Photos on CD & DVD, MAGIX Movies on CD & DVD and MAGIX Movie Edit Pro 2004 as well as every other WAV-compatible slide show or editing software.