text: Stephen Thomas Erlewine of AllMusic found the album's omission of "Dope Hat" (1994), "Man That You Fear" (1996) and "I Don't Like the Drugs (But the Drugs Like Me)" (1998) "curious". He added that "Nevertheless, [Lest We Forget] has enough of the hits to make this worthwhile for the casual fans, as well as those listeners who never wanted to admit that [the band's] late-'90s alt-rock radio staples were guilty pleasures." In his book Dissecting Marilyn Manson, Gavin Baddeley opined that "for an album artist like Manson, [greatest hits] collections do fly in the face of the careful structure behind his best work, where the running order is an intrinsic feature of the package." Baddeley felt that, like the band's EP Smells Like Children (1995), "Lest We Forget is redeemed by a clever cover of an eighties pop song, in this case Depeche Mode's 'Personal Jesus'". Writing for PopMatters, Lance Teegarden described the band's cover of "Sweet Dreams (Are Made of This)" (1995), "The Beautiful People" (1996) and "Mobscene" (2003) as "[a] few choice hits on a far too lengthy and same-sounding best-of."
  Commercial performance
  Industry forecasters predicted the album was on course to debut on the Billboard 200 with first week sales of around 60,000 units. It went on to debut at number nine on the chart, selling 78,715 copies on its first week. It would spend a total of 27 weeks on the chart, and was certified gold by the Recording Industry Association of America in October 2005 for shipments in excess of 500,000 units. As of November 2010, Lest We Forget had sold over a million copies in the United States. It also debuted at number three on the Canadian Albums Chart.