Izmailovo is a huge hotel complex (more than 4000 rooms) built to host the 1980 Olympic Games. It's probably the best option for budget travelers to Moscow as it offers solid 3-star accommodation for a very competitive price: you can get a double room for about €60 during the high season there.
The hotel is situated just next to Izmailovsky Park, which is great for walks and various activities — you will especially appreciate this as Moscow is pretty polluted, so it's great to live next to a park. The city center is about 20 minutes away by metro and 20-40 minutes by car (€10 for a taxi ride one way), depending on the traffic, so it's pretty accessible too.
There are several hotels in Izmailovo complex: Izmailovo Gamma-Delta, Izmailovo Alpha and Izmailovo Vega being the main ones. They are more or less the same, so your main consideration should be the price. Izmailovo Vega is part of the Best Western chain, while Gamma-Delta and Alpha are run by other operators.
Your neighbors will be very varied: from budget tourists and flocks of Chinese sight-seers to Russian entrepreneurs and various dodgy but non-dangerous characters. Occasional offers of sushi and prostitute room delivery might occur, but those can be easily dealt with depending on your willingness to engage.