It's been a few years, but I have stayed at President Solitaire and liked it. It's a very long walk back (15-20 min) to Sukhumvit down Soi 11, though an entertaining one to be sure. It's convenient to Bumrungrad Hospital down the back Green Route road, which is why I chose it then. Or avail yourself of the motorcycle taxis that go back and forth down the Soi.

Soi 8 is a great soi to stay on also, as long as you are not way down towards the end. Adelphi would be worth looking into. Majestic Grande on Soi 2 would be too noisy a location for m, sandwiched between Nana nightspots and the expressway.

Earlier this year, I stayed on Soi 15 at Kingston Suites and thought it was extremely good value for what I paid for a Hot Deal on a Deluxe room w/brkfst (agoda.com)--Rooms are quite large though they don't have kitchenettes like Solitaire does. It's a smaller hotel so no big groups. Very well located, about 5-6 minutes walk from Sukhumvit but far enough down to be quieter. It's just down the street from Four Points Sheraton. I liked proximity to Asoke station since I needed both Skytrain and subway on that particular trip.