Like everyone else said, most groups would love a NIN for their Trick Attack and RDM is very good to have for PUGs and for learning a fight. SMN is in a weird place, to a lot of people it can feels clunky BUT it has a great balance of damage and party-utility, being able to buff the parties damage (Aetherpact), Swift Cast rez a KOed partymember (or even hardcast in more casual content), and place a regen-effect on all partymembers when they summon Phoenix (granted, it might not always be at a useful time). However, SMN is one of those jobs that changes almost every expansion, so we'll have to see. :B

For more mildly nice jobs:
-BRDs have songs that provide small, party-wide buffs that they rotate through, a buff that increases the party's Direct Hit by 20% (Battle Voice), an ability that can either cleanse a cleanseable debuff or shield a target from a cleanseable debuff (The Warden's Paean), and a buff that reduces damage the party takes (Troubadour). BRD's main focus is to place and maintaining their 2 DoTs on enemies and rotate through their three songs, gaining different RNG procs with each song every DoT tick. You also gain points in a gauge every time you proc with a song that can be used on an oGCD attack (Apex Arrow). BRD is physical ranged.

-DNCs can partner up with another partymember to buff them (and themselves) with Standard Step and Devilment, can buff the party with Technical Step, have an AoE healing oGCD that heals everyone around them AND their dance partner (and I think both stack) (Curing Waltz), a buff that reduces damage the party takes (Shield Samba), and one of the best mobility tools in the game (En Avant). DNC focuses on maintaining your Standard Step (via a little mini-game) while gaining RNG procs from your weaponskills, which randomly grant you stacks called Feathers that you can use on one-of-two damage abilities (Fan Dance and Fan Dance II), which can then randomly proc another ability (Fan Dance III), while also randomly gaining points in a gauge from everyone under your Standard and Technical Steps to use on a powerful attack (Saber Dance). DNC is physical ranged.

-DRGs can increase the Critical Hit of all partymembers with in range (Battle Litany) and buff both their's and another partymember's damage (Dragon Sight). I'm not as versed in DRG but from what I understand, they used and maintain their Blood of the Dragon buff while, which grants them access to two stronger weaponskills that help maintain it, while also gaining Gaze stacks whenever you use Mirage Dive. Once you have 2 Gazes, you can use Geirskogul, which changes Blood of the Dragon to Life of the Dragon for a duration, changing Gierskogul into Nastrod. The job is some what positional heavy, having 2 weaponskill combos, one for rear and one for flanking. DRG is melee.