— print usernames and the roles assigned to the user, it can be run against any database and it will print the users and the roles assigned to different users
SELECT sl.name, g.name
FROM sysusers u, sysusers g, sysmembers m, master.dbo.syslogins sl
where g.name IN (SELECT name FROM dbo.sysusers WHERE ([issqlrole] = 1 OR [isapprole] = 1))
and g.uid = m.groupuid
and sl.sid = u.sid
and g.issqlrole = 1
and u.uid = m.memberuid
and sl.denylogin = 0
order by sl.name

Sample output:
localuser db_owner
localuser db_datareader
domain\ADuser db_datareader
domain\ADuser db_denydatawriter
….