On a more serious note:
Do you like short races?
Dwaves, Halflings, Gnomes, and Dark Elves (some what).
Do you want awesome functional abilities no other race has?
Hide is limited to Dark Elves and Halflings. Not nearly as OP as it used to be but still good for AFKs in some areas.
Sneak is what puts Halflings over the top for me. It allows you to use merchants, explore and gain access to quests that the other races can not do without a lot of faction work or having to use invis/calm.
Dwarves have innate + magic resist, if you plan to PVP it could help.
Do you like to use wall scoping to see what is on the other side?
Dwarves, Gnomes, and Halflings get this ability without the need for shrink. Dark Elves can do it to some extent.
Do you want to wear robes?
Kunark and
Velious best in slot pieces for clerics are both robes. Leaving Dwarves and Halflings in the cold. Plus there are some other nice looking robes clerics can wear for fashion purposes.
Do you want cool clickies?
Erudites/Humans get some cool clickie item quests in Paineel.
Gnomes can tinker some cool stuff up.
Dark Elves have access to a snare necklace.
Dwarves get a summon beer clickie in Velious.
Do you want to wear awesome racial/deity armor?
Dwarves and Gnomes (Brell). To a lesser extent Dark Elves (Innoruuk).
Do you mind being an evil race?
Dark Elves, some human, gnome, erudite deity combos
Do you want 5% xp bonus?
Halflings! Although once you hit 60 it becomes moot.