CREATE TABLE party_forms (form_id VARCHAR)
CREATE TABLE forms (form_name VARCHAR, form_id VARCHAR)

Find the name of the most popular party form.
SELECT t1.form_name FROM forms AS t1 JOIN party_forms AS t2 ON t1.form_id = t2.form_id GROUP BY t2.form_id ORDER BY COUNT(*) DESC LIMIT 1
SELECT "t1"."form_name" FROM "forms" AS "t1" JOIN "party_forms" AS "t2" ON "t1"."form_id" = "t2"."form_id" GROUP BY "t2"."form_id" ORDER BY COUNT(*) DESC NULLS LAST LIMIT 1