Travel question?

What are the best plushies/flowers to buy and what countries are they from?

Mexico 

I base my flights around my irl schedule. Sure some places boast better rewards but only if you're there on the button to buy and fly straight out and repeat. 

By meaning best plushies/flowers, I assume you mean most profitable. Profit is calculated by profit per hour per item. At the time of writing, best profit per minute for flowers is 163.58 $ by Peony flower from China closely followed by 163.52 $ by Cherry Blossom from Japan. In Plushies, best profit per minuter is 164.65 $ by Panda Plushie from China followed by 161.21 $ by Camel Plushies from UAE. This listing would fluctuate. Keep an eye on Tornstats to know the updated listing.

You have to know the definition of profit per minute assumes that you non stop fly and the items are always available in the specific market which are not true. Often the flowers/Plushies go out of stock forcing you to wait abroad for them to spawn back again. This in itself extends your to and fro flight time and profit per minute in those cases drop.

So it is safer to plan your flight based on your RL schedules. If you are busy person, You can do two or three UAE or China trips a day. Or If you can log in like a robot at the specific time, You can do four/five trips to Argentina. You should aim to touch 5 Million profit per day or at least close to it. For more details, read my thread Which plushie is profitable. 

The ones you don’t get tired of going to get.

I recommend a good third party tool like TornPDA that helps to determine profiability and availability before flying.  High profit items don't help you if they are out of stock when you arrive.  Staying overseas in a country waiting for restocking is a good way to get mugged.  Quickly make your purchase and leave during the 15 second grace period.  I prefer setting timers or alarms on my phone to the TornPDA alerts which are sometimes a little late or quite a bit too early.

The other important thing to consider is natural energy and nerve lost on longer flights.  I generally avoid the farthest countries for this reason unless I happen to be stacking energy for a war.

5 trips to Argentina is over 20 hrs a day, which would leave a little under 4 hours for sleeping IF you only land briefly each time. I don’t think that’s really achievable/sustainable for most people… even with 4 flights, you still need to be very disciplined to not waste time and stay on schedule.

I barely get 2 flights in to the UK most days tho, so I’m a pretty lazy flyer. Idk if it’s just me but I get distracted looking at the item market, or sit around waiting for xanax cooldown, etc. 

If you are trying to maximize profit and not waste natrual E I would recommend UK, there are 2 plushies and 1 flower there so odds of at least one being in stock is usually very high. You will come back to Torn with out capping your natural E. I usually get 3 flights in a day to the UK. 

If I am stacking for war or a chain I will pick the further flights since I wont be getting natural regen. Right now I use those times to work on my 50 flights to X