Built in Targeting:
Cycle Through Enemies (Nearest to Farthest) Tab
Cycle Through Enemies (Farthest to Nearest) Shift+Tab
Face Target F
Target Self F1
Target Members in Party List F2 - F8
Target Pet/Familiar F9
Target the Target of Your Current Target T
Target Focus Target F10
Target Nearest Enemy F11
Target Nearest NPC or Object F12
Set/Clear Focus Target Shift+F
Cycle Up Through Enmity List Ctrl+NUM8
Cycle Down Through Enmity List Ctrl+NUM2
Cycle Through Alliance List (Forward) Ctrl+NUM6
Cycle Through Alliance List (Backward) Ctrl+NUM4

Text commands:
　/targetenemy, /tenemy
→Targets the closest enemy within a certain radius.

　/battletarget, /bt
→Targets the closest enemy within a certain radius that is attacking you.

　/assist, /as
→Targets the target of another PC. Assists current target when none is specified.

　/nexttarget, /nt
→Toggle clockwise through on-screen enemies.

　/previoustarget, /pt
→Toggle counterclockwise through on-screen enemies.

　/targetlasttarget, /tlt
→Re-target your last target.

　/targetlastenemy, /tle
→Re-target the last enemy you targeted.

　/autotarget [subcommand]
→Enable auto-target when no target specified.
>>Subcommands:
　on Enable auto-target.
　off Disable auto-target.
Toggle between on/off when no subcommand is specified.