I have been looking for a good multiclass for a monk, because I'm curious and will be joining a high-level campaign soon and wanted to know some good options. I have been considering a level 8 monk plus level 3 druid, but I'm also considering cleric or rogue instead of druid. I don't want a min-maxed character, but it should still be decently powerful. Mainly, I'm looking for something fun to play. I'm joining a campaign at a local comic store, so I don't know what the other people are playing. I just need a few good ideas. Also, the PHB states that a druid in animal form retains their class features. If I was a multiclass monk + Druid, could I use Flurry Of Blows as an animal? thanks in advance for the feedback. 

I’ve always wanted to do a monk/cleric build and use spirit guardians, more deadly now if you are using 2024 rules. It requires 5 levels in cleric so that may be more than you are looking for. 

Druid is always good and I don’t see why you wouldn’t be able to use FoB. But I’m no Wild shape expert.

And Ranger is also good if you only want three levels. Hunter’s colossus slayer or Gloomstalker’s Dread Ambusher features can help out. 

But play what you will have fun with. 

Like mentioned,  cleric, Druid or ranger would make great MC choices. It’s basically what you enjoy, or what the “group” may need. 
personally, I’m a fan of Ranger (3) levels, grabbing gloom stalker as it gives bonus that plays well with my group.

example, with the addition of adding Wis mod to initiative (half free alert feat). 
but clerics and druids have their flare (especially with subclass features. So basically pick your poison, skies the limit. 

Best advice is ask your group what they think would bring more advantages to the party. But not sacrificing what you may enjoy playing along as well.

hope this helps you out!

The fact that now the monk 2024 has bonus action attacks independent of the action attack allows it to combine magic with unarmed attacks. So magical or semi-magical classes (cleric, druid and ranger) are a good option that offer many combat variables.

Classes such as warrior and rogue also have good synergy.
The warrior offers an optimized system with two weapons and unarmed attacks. While the rogue when combined with the shadow monk's teleports can offer easy sneaks att and combine them with its special techniques.

I find that this new version of the monk is more open to multiclassing and this makes it much more interesting

Certain sub-classes of rogue would thematically fit with shadow monk as a multi-class. Soul knife and assassin would make a shadow monk into a ninja. 

Dipping three levels into Fighter and going Battle Master will give you a bunch of extra stuff that will compliment having Monk as your man class.

Am currently doing a elemental monk 5/ land Druid 3.

So far, my main gig is the cheesegrater of grapple and run beside the spike growth. Haven’t considered using wild shape with monk flurry. Not sure it is that effective unless you chose a moon Druid. 

start with 3 levels or rogue possibly assasin but they all work and than go way of the shadow monk 2024. You will be the ultimate stealth character. using ki to cast darkness, pass with out trace, or silence and even minor illision. At 6th level you get shadow step and can move from shadow to shadow or in darkness up to 60 feet away and your next attack is with advantage so you will get your 2d6 back stab with a dager or short sword(both Monk Weapons) and all monk attacks. Shadow step is not a Ki based feature, once per turn. Cloak of Shadows at 11th level is an action to become invisible in shadows or darkness.

If you enjoy stealth, and bouncing around combat from shadow to shadow it will be a blast.

You could always multiclass as a Dance Bard for a more powerful unarmed gish character as well. Hold Person + Flurry of Blows FTW!

I have a three class build. Monk 7th lv(drunken)/fighter 4 lv(living cauldron)/ cleric 1st level (peace domain). Still playing on the older rules. My main role in the game is a support tank using bless mixed with emboldened bond so allies have 2d4 on saves or attacks in combat while I use living cauldron ability’s to half physical damage as I dish out consistent damage. Any thought on how I can grow from this as I progress level wise or should I stick to this tactic? Str:10/dex18/con16/int10/wis14/cha:18(alt stats use,dex&cha for monk ability’s) main weapon long sword/Eldritch claw tattoo once per day)

I think Monks, are challenging to play in combat because of all the things to keep track of, and with the complexity of a Druid added on top, it would be a bit much for me.

As a multiclass in Cleric would simplify things down a bit. How many minutes on your turn, keep it fast. Combat should not last more than 4 or 5 rounds with the new mm.

follow the bliss of the group.

currently playing a Shadow Monl lvl 14 and cleric of Twilight lvl 4. Lots of fun and some synergy between twilight and shadow.

Planned next character will be a blind haregon monk/cleric with blindsense (dm granted feat) and magic initiate for general familiar's longer range vision when needed.

If we get as far as lvl 15, then I imagine it'll b 6 shadow (mainly for poetic flavour) monk/9 trickster cleric. 

Can do some serious damage with grapple and spirit guardians, plus lots of other shenanigans n rp opps!

Good multi-class too based on both monks and clerics relying on wisdom as a key stat!

Even one level of ranger has been a big foundational boon to Monk for me. Two weapon masteries, Nick and vex being easy picks at least, an extra skill proficiency, and most of all hunters mark. By the time your flurry of blows is hitting 3 times, plus extra attack from Nick (but bonusless), you’re hitting potentially up to 6 times which means an additional 1-6d6 against a target per turn. And that can include effects like Hand of Harm. It’s substantial low cost damage. And since Ranger is also dex/wis centric there’s basically no downside.

the only one is that the monk 20 capstone, if you’re planning on going there, is quite powerful now and a big trade off, but in my experience Ranger dip has just been nothing but good for my monk.

Any cleric dip for the bane spell to increase the potency of stunning strike.

Fighter dip for fighting styles - two wepon fighting, weapon masteries and action surge.  Kensie/Battlemaster pair really well.