By bus : From Arusha to Dar Es Salam
As a traveler on budget, I'm always looking for ways to save up (ain't yet to that 6 figures salary so gotta dig hard to find ways to save tho tbh even if I was at this point I would still choose these options for the sake of experience). People will call me crazy or cheap because I decided to board on a 12 HOURS RIDE from Arusha to Dar Es Salam, but it wasn't that bad 😌
After thorough research (google and asking my kenyan friends, I decided to go with Tahmeed Coach

I used Tahmeed bus and all I can say is WOAAAW , Woaw is not even the word! 😯
Their buses are so niiiiiice! Big spacious seats with LED lights and HD touch screen where you can listen to music, play games and even watch movies !!! If a 12hours ride to Dar Es salam sounded exhausting, they surely make it easier ! I honestly didn't feel like it was long because the ride was very nice and comfortable

"During the ride they offer bottled water and make stops every 2h30mins for food and washrooms the longest one being 20 mins! They also let vendors in sometimes so that you can buy food (apples, peanuts , chocolate, sodas etc ) How great is it ?"

Other than that, the check-in process is pretty easy. I had my ticket already printed out because I booked in advance through their website (you can only book online through MPESA so find someone who has it). If you can't take your ticket on the website, you will just have to be at the station 30 mins before your departure time to buy a ticket from their office.
They are open even in the early morning (my bus was at 6 am and was there at 5:30am).
Seat assignments are respected so it's pretty hard to change your seat once you select your seat, unless the bus isn't full and you can move around :). Also, keep in mind that the space with two seats is more spacious than the single one
They gave me another ticket , a more official one which was also really cute ☺️
The only cons would be the fact that some of their seats have issues: they don't recline at all or just can't be adjusted. It makes it unfair for those seating behind given that it makes your leg space tighter. They should think about fixing it. My seat had an issue (wasn't reclining) but a really nice guy accepted to exchange his seat for mine ( shoutout ️🧡 to you stranger)
Overall, the bus is clean, smells good and is well maintained. For 2000 Kshs, I think my money was well spent !