Hotel Flamingo has to be the best budget accommodation in Arusha if not all of Tanzania and East Africa. You will not find a cleaner place to stay for the price; at the time of this writing a double went for 30k TSh and a single for 25k TSh with breakfast included. We reserved via email with Ian who replied promptly and professionally. When we arrived, our spotless rooms were waiting. The staff are genuinely nice people, not the I-want-to-sell-you-something-type of nice and their focus is providing their guests with quality service.
The sheets and towels (which they replace with new ones each day) are a crisp white; they even go to the extent of replacing the soap with new ones daily. Compared to other budget accommodations where you kind of cringe getting into bed, speculating on how clean the sheets are, etc., we had every confidence that our bed was clean. Pricier hotels do not work as hard as the staff at Flamingo does at maintaining such a high level of cleanliness. In fact, you will see the staff mopping the floors several times a day.
Unlike other places, we were not pressured to use other additional "services" they provide. When we asked them where the Maasai Market was, they kindly showed us the location on a map and gave it to us to use for the day. There was no "I can arrange a guide to take you" sort of deal, which is a refreshing, and appreciated change.
Other perks include:
1. the cheapest laundry service we found in East Africa (pants/shirts for 500 TSh)
2. conviently located near Khan's Barbecue, the best cheap dinner in Arusha and a short walk from the central bus station
3. brewed coffee at breakfast, not coffee house good but not instant either
4. 24 hour hot water with good pressure
The only negative to staying here is that it is near a mosque and the pre-dawn call to prayer will sound like it comes from next door. But there are many mosques in Arusha and chances are that you will be sleeping near one anyway.
Hotel Flamingo is one of those places we felt really glad we stayed at and we can't say enough about it.