Chaos is a popular choice for a remake it seems. (With Ataxia being my effort.)
Here's a list of other remakes created by fellow Spec-chums and strategy game fans.

• Chaos Funk is a pretty faithful remake with nice crisp graphics (based directly on the originals). http://www.reflectedgames.com/free.html
• Chaos Groove by Richard Phipps. Rich has started development on a new version of Chaos Bass and renamed it Chaos Groove! - http://chaosgroove.wordpress.com/
• Realtime Chaos allows multiple players to play together over a server... but in realtime! Haven't tried it yet. http://www.carlylesmith.karoo.net/realtimechaos/
• Chaos Reborn, developed by Erik Benerdal, has gorgeous anime-style sprites and all the whoosh-bang effects I wish I knew how to program. It's not 100% finished yet and thankfully he hasn't messed with the original rules too much. http://www.scalari.net/chaos/index.html
  
• Total Chaos. I remember playing Total Chaos AGA on the Amiga during the late 90s, and apparently this series is still going strong. http://xavprods.free.fr/chaos/index2.html
• Chaos for the Gameboy Advance! http://www.geocities.com/quirky_2k1/games/chaos/index.html
• Anarchy was an attempt at making a 3D Chaos, unfortunately unfinished. Cute in a low-fi way. http://www.btinternet.com/~t.harte/SoftySoft/anarchy.htm
• Cyber Battles. Internet multiplayer sci-fi version. No-one was logged in when I registered, so don't know what this is like yet. http://www.duelboard.com/old/multiplayer.php
• Out of Chaos. Coded by Sinister Systems. This is a 'integrated remake' of two classic Spectrum games, Out of the Shadows, and Chaos. - http://www.sinistersystems.com/dokuwiki/doku.php?id=geeny:projects:chaos#out_of_chaos/
  • The style of floor tiling in Out of Chaos reminds me of the Heroquest boardgame. Quite exciting looking.