The largest sui juris churches are the Latin (Roman or Western), the Ukrainian, the Syro-Malabar, the Maronite, and the Melkite, all of which have over a million members worldwide. The Albanian, Greek, Russian, Belarusian, and possibly Bulgarian churches all have less than 10,000 members worldwide.
They can be compared in a number of ways, of which the two most common are by the family of liturgical rite of which they are a part and by how the head of the church is positioned in the episcopal order of precedence. The former gives a better sense of how the church actually operates, but the kinds of elevation done by the Pope concern the latter.
Liturgical Family
These can be thought of as 'cultural units' in the Church, sharing liturgical rites and often liturgical languages. According to the Catechism (CCC 1203):
The liturgical traditions or rites presently in use in the Church are the Latin (principally the Roman rite, but also the rites of certain local churches, such as the Ambrosian rite, or those of certain religious orders) and the Byzantine, Alexandrian or Coptic, Syriac, Armenian, Maronite, and Chaldean rites. In “faithful obedience to tradition, the sacred Council declares that Holy Mother Church holds all lawfully recognized rites to be of equal right and dignity, and that she wishes to preserve them in the future and to foster them in every way.”
Alexandrian
(The primary liturgical languages are Coptic and Ge'ez.)
Coptic
Ethiopian
Eritrean
Antiochene
(The primary liturgical language is Syriac. The Maronite Catholic Church is sometimes distinguished out as somewhat different from the others in the family.)
Maronite
Syrian
Syro-Malankara
Armenian
(The primary liturgical language is Armenian.)
Armenian
Byzantine
(There are multiple liturgical languages; Greek is the dominant one, followed by Church Slavonic, but they are quite diverse. What primarily unites Byzantine churches is that the basic structure of their liturgies is more or less the same, and derived from a Greek original.)
Albanian
Belarusian
Bulgarian
Croatian
Greek
Hungarian
Italo-Albanian
Macedonian
Melkite
Romanian
Russian
Ruthenian
Slovak
Ukrainian
Chaldean
(The primary liturgical language is Syriac.)
Chaldean
Syro-Malabar
Latin
(The primary liturgical language is Latin.)
Latin
Juridical Status
As all sui juris churches are equal in dignity, order of precedence does not indicate the importance of the church itself, nor of any of its members as Catholics, but only the status of the head and his authority, as recognized by the juridical authority of Rome. It thus reflects how the church is organized and governed. This difference arises from a number of reasons, such as history, size, organizational complexity, or political complications. Thus, for instance, the second largest sui juris church is the Ukrainian Greek Catholic Church; it has the size, organization, and influence that usually raises its head to the status of Patriarch, and in practice Ukrainian Catholics even call the head of their church 'Patriarch' and treat him as such, but Rome has been reluctant to confirm this status officially due to complications in relations between Catholics and Russian Orthodox, so its head officially has the in-between status of Major Archbishop, which indicates roughly that the head of the church functions in practice with full patriarchal authority and eminence but that there are reasons for not actually saying this.
A crude analogy to secular political units can be used to get a sense of what these indicate. Eparchial status can be seen as indicating a kind of coherent 'autonomous region' within the Church ('eparchy' is the eastern version of 'diocese'), whereas full-blown Patriarchal or Major Archiepiscopal status always indicates that the status of the Church is more analogous to that of a sovereign nation -- the Pope is still a higher tribunal and can impose canon laws, but with respect to other patriarchal churches, the Pope is himself also obligated (although the extent is a bit indeterminate) to respect precedent, custom, and usage; and in practice the Pope tends to intervene only in matters arising between particular churches. But it's important always to remember that, unlike secular political units, each sui juris church, whether it is patriarchal, eparchial, or otherwise, is itself the Catholic Church in one of its liturgical-juridical forms, and not a mere sub-unit of it.
Patriarchal
Latin
Coptic
Melkite
Maronite
Armenian
Syrian
Chaldean
Major Archiepiscopal
Ukrainian
Romanian
Syro-Malabar
Syro-Malankara
Metropolitan (Archiepiscopal)
Hungarian
Ethiopian
Eritrean
Ruthenian
Slovak
Eparchial
(These often have no single head, but they do have authoritative structure, since they have bishops in charge with of their own eparchies/dioceses, and they are united by history, culture, and the protection of the Pope. Some of these, like the Albanian and the Greek, are not strictly speaking eparchies and so could be listed as 'other', but in practice function mostly as if they were. The Albanian is an Apostolic Administration and the Greek Catholic Church is an Exarchate.)
Albanian
Italo-Albanian
Bulgarian
Croatian
Greek
Other
(These often are churches with a history as sui juris churches that still technically exist but now only exist in small and scattered form, usually due to major disruption like civil wars or population collapse, or else that for one reason or other needed to be split off from another sui juris church. The head may be a deputy of a patriarch of another church or there may be no head. The Belarusian and Russian churches no longer have any bishop at all, if I understand correctly. The Macedonian Greek Catholic Church is a former part of the Bulgarian Greek Catholic Church.)
Macedonian
Belarusian
Russian
