Strictly Come Dancing (Partially found Series 1-4)

Strictly Come Dancing (often shortened to just "Strictly") is of course a very popular reality TV show featuring C-list celebrities taking on ballroom dancing. It first aired on BBC1 on 15th May 2004 and it is a staple of the Autumn Saturday night schedule. It is currently hosted by Tess Daly & Claudia Winkleman. There is short of content from the first 4 series that is available to watch online.

Findings
Content of the first 4 series are hard to find online, and is considered to be lost media. However, Series 1, Episode 1 was uploaded to Vimeo in 2016. YouTuber and dance enthusiast Antony Palmer has uploaded Series 2, Episode 1 titled "STRICTLY COME DANCING 2001" (even though the talent contest didn't exist back then), Series 3, Episode 10 (2005 final) & Series 4, Episode 12 (2006 final). The latter 2 aren't full episodes, just excerpts. Other than that, there isn't anymore full episodes between Series 1-4, only focusing on recent years as per usual.

Clips that are available online
Minor YouTuber Flimango & Chuck had created a playlist entitled "Strictly clips that are on YouTube", consisting of clips of individual dances and interviews from Series 1 & 2.