Let me help are you still in Kenya 🇰🇪 lol 

 No, out of Kenya since a little while 😉 lol  

 Ah 

 Hm, if you only use it in Linux environment I would go for xfs or btfs. If you plan to use it also in Windows machines maybe exfat 

 Strange, no ext4. I see another reply suggests XFS and Btrfs. I disagree with XFS, it is mostly meant for storing large files, whereas during common use with user files, and config, you get a lot of small files.

You could use Btrfs, while normally it is pretty stable, and has some advanced features like snapshots, when it does break, the recovery tools are really unfriendly for normal users. Since external drives are not usually very high reliability, I would be slightly hesitant. IMO, ext4 is the tried and tested, reliable choice. 

 Agreed, i would also prefer ext4 in general, but as it was not an option... But it's strange, every Linux should be able to format almost everything in ext4 

 Ext 4 is an Option on the first step. But Android didn't like ext4.  

 If just to transport data around without working on the files directly on the stick, I would go with exFAT for compatibility reasons.

Otherwise, I would go with ext4 (that oddly don't show there) since its really hard do corrupt, and sudden disconnections are a problem with removable drives. 

 Ext4 is in the first step. I just try F2FS at the time. It is really fast. The exFat I use for those I want to save/backup data and keep them compatable with my Android Phone. 
1 USB Stick and my big external SSD, i make F2FS, my USB Stick I encrypt (for sensitive Data) I make F2FS (maybe later ext4) and the other plus small SSD with exFat. 
Thats my Setup I thought about during the day. Let's see how it works out  

 Careful there. F2FS has a notoriously weak FSCK (nearly useless) for recovering the file system in the event of failures. It's the type of filesystem truly intended for use on embedded systems with read-only storage or devices with a battery attached. Using it on a removable device is inviting trouble.

If you genuinely don't want ext4 for some reason, at least opt for btrfs, which has more developed user space tools. 

 Ok, I didn't know. I did read btrfs is not that good for removable devices. 

So F2FS is basically the russian Roulette type? 
Maybe for the encryted stick I change to ext4.
But for the 2tb SSD I want Something fast! What would be the best solution on that! I want to work on the drive. 
Those I want to access on other devices I make exfat.