The Mote in God's Eye by Larry Niven and Jerry Pournelle. First read it as a teen in the 80s and still rate it as one of the best SF books ever written. Well p

The Mote in God's Eye by Larry Niven and Jerry Pournelle. First read it as a teen in the 80s and still rate it as one of the best SF books ever written. Well paced and enormous fun. The Player of Games by Iain M Banks. Probably the most self-contained of the Culture series and the least heavy SF of them. Which makes it a great starting point.