Restoration movement

The Restoration Movement is a Christian movement started in the early 19th century by the Campbellites, who believed all the churches had fallen into apostasy and they were restoring the original church (sound familiar?). They reject the term 'denomination' and often insist the correct rendering of their name is 'church [or churches] of Christ', leaving church uncapitalized. They hold beliefs close to most other evangelical Christians', but are perhaps best known for their rejection of the use of musical instruments in church services, because they are not specifically mentioned in the New Testament, so whatever you do make sure to set your cellphone to vibrate; don't leave it on ring tone.

The Campbellite movement was also known as the Stone-Campbell and some scholars group the churches of Christ, and several other new religious movements of the 19th century (such as Mormonism and Seventh-day Adventism), in the separate category of Restorationism, distinct from Protestantism.

One of their early leaders in the 1800s was David Lipscomb, who has seen renewed interest lately for his individualist anarchism and Christian pacifism views, neither of which appears to be influential at all in the modern Church of Christ.

Related liberal denominations
The Christian Church (Disciples of Christ) is a rather tame mainline denomination with Campbellite roots.

Unrelated liberal denominations
The is a theologically and socially liberal denomination with no relation to the Church of Christ. They used to be known as the Congregational Church.

Another unrelated denomination (not so much liberal)
The Church of Christ, Scientist has a similar name, but despite the "scientist" part, it doesn't actually involve real science, with its followers rejecting modern medicine in favor of praying sickness away... well, trying to, anyway.

Nuttery-buttery splinter movements
Peter J. Peters is a Church of Christ minister who holds beliefs more in line with Christian Identity.

Moronism has some roots in the Campbellite movement. Sidney Rigdon, one of Joseph Smith, Jr.'s close associates, had been a Campbellite before converting, and many of Joseph Smith's early Mormon converts came from the Campbellites, including some entire congregations who converted en masse. Smith called his early Mormon church the "Church of Christ", before tacking on the more ostentatious bits.

The Aquarian Gospel of Jesus the Christ was the work of a Church of Christ minister who claimed he obtained the text from the Akashic Records.

The Boston Church of Christ is a related denomination best known for the Discipling and Shepherding movement.