After Taiwan joined WTO, Son May and Ever Anime (as shown in the comparison photo below, top is a legit Polygram label, the bottom is a bootleg Ever Anime label) have ceased to exist (although there are still many stores selling their stockpile of bootlegs). There are still some companies that lived on though. One such company was known as "Smile Records", there might be more, but I haven't been keeping up with news on bootlegs anymore.
Besides CDs, there's also companies that do the video. They take the LD or TV captured footage, chunk in subtitles (usually Chinese and poorly translated English), then burn them onto VCDs and/or DVDs. Of course, these are copyright violations and customs officers love to confiscate these.
Do keep in mind that just because a VCD/DVD have Chinese subtitles doesn't automatically make it a bootleg. There are some companies in Asia that sell legit Anime VCDs/DVDs and have readable English subtitles.
Usually it is hard to determine just by the packaging as bootlegs tend to use the same packaging as the originals. Instead, the easiest way to tell the difference is by price and episode count per disk. Bootlegs are much cheaper than originals (usually at a fraction of the original's price), tend to cramp as much episodes as they can per disk and rarely come with extras.