JW's believe only 144,000 go to heaven. The 144,000 are carefully chosen (anointed) by God. Interestingly though, the Watchtower Society (WT) can veto God's top picks and excommunicate or 'disfellowship' them if they disobey Jehovah's rules. See this secret rule book for JW Elders Shepherd the Flock of God
Up until 2012, the 144,000 were called God's 'faithful and discreet slave'. Since most of 144,000 have already died, only a small 'anointed remnant' remains alive today. [1a] [1b] 
Today, the 'anointed', 'anointed remnant', and 144,000 are no longer special. The Watchtower says their Governing Body is God's faithful and discreet slave and has served in that capacity since 1919. 
Millions of Jehovah's Witnesses (i.e. 'the great crowd') believe they will live forever on a paradise earth.
Only 144,000 go to heaven because only 144000 'spiritual Israelites' have a relationship with Jesus.
The 'remnant' refers to the 144,000 spiritual Israelites who are still living today. The 144000 is comprised mostly of JW's.
The Watchtower says, 'To keep in relationship with "our Savior, God," the "great crowd" needs to remain united with the remnant of spiritual Israelites.' 
It sounds like unity with members of the 144,000 is required in order to be saved. However members of the 144,000 can get disfellowshipped and lose their position in heaven. The 144,000 must obey congregation Elders and the Governing Body just like Jehovah's Witnesses who are part of the 'great crowd'. 
This makes it clear that the Governing Body makes the rules and enforces them. The 'anointed remnant' and 'spiritual Israelites' (i.e. 144,000) has no authority in the organization. JW's are not 'united' with the 144,000. All JW's are required to obey a few men in Brooklyn who appear to be in an exclusive relationship with Jesus.
1a. The Watchtower says this. 'Jesus Christ, is not the Mediator between Jehovah God and all mankind. He is the Mediator between his heavenly Father, Jehovah God, and the nation of spiritual Israel, which is limited to only 144,000 members. ' WT Book: 'Worldwide Security', 1986, Chapter 1, 'The Desire for Peace and Security Worldwide', par 16
1b. The Watchtower goes on to say, 'They recognize that they are not spiritual Israelites in the new covenant mediated by Jesus Christ, nor part of the "chosen race, a royal priesthood, a holy nation."-1 Pet. 2:9. 24 Yet they do benefit from the operation of the new covenant. They benefit from this just as, in ancient Israel, the "alien resident" benefited from residing in among the Israelites who were in the Law covenant.-Ex. 20:10; Lev. 19:10, 33, 34; Rev. 7:9-15. 25 To keep in relationship with "our Savior, God," the "great crowd" needs to remain united with the remnant of spiritual Israelites." Watchtower Nov 15, 1979 page 27 Benefiting from "One Mediator Between God and Men"
2. 'Spiritual Israelites' and the 'anointed remnant' of the 144000 (faithful and discreet) 'slave class' must obey congregation Elders and the Governing Body of JW's, just like millions of JW's who belong to the 'great crowd'.
Notice what the Watchtower says, 'a limited number of anointed men have the responsibility of representing the slave class. They make up the Governing Body of Jehovah’s Witnesses. .. Whether we are “domestics,” who are part of the anointed remnant, or we are members of the great crowd, let it be our determination to cooperate fully with the faithful steward and its Governing Body.' Watchtower June 15, 2009, Article: 'The Faithful Steward and Its Governing Body.'
3. For many decades JW's believed God's anointed remnant of the 144,000 was God's 'faithful and discreet'. JW's thought that the 144000 were leading the organization and making the rules. In 2012 the Watchtower announced that their anointed Governing Body (8-12 men) is God's faithful and discreet slave and always has been leading the organization since 1919.
JW's are now required to believe that the Watchtower's Governing Body is God's slave. This means God speaks to the Watchtower and the organization tells JW's what God said. Also in order to be saved by Jesus and earn eternal life on a paradise earth, JW's must be 100% loyal to 'God's organization' and obey all of Jehovah's rules. See Watchtower Quotes: "Who Really Is The Faithful And Discreet Slave?"