If you're around the University (Highfield/Portswood area), then drop in at the Crown Inn on High Crown Mews. The menu's been a solid favourite for locals, students and lecturers for years, and brilliant value for money.
Any visitor ought to try the Crown Inn Burger at least once: you won't be disappointed. Their Sunday Roast is also good value.
SO17 1QE http://www.crowninnhighfield.co.uk/