I’ve been happily living the ‘Good Life’ in Surbiton for the last 14 years, prior to that lived in Epsom after some time spent living in Chertsey! The links into London are excellent and it’s also got good bus links. The Surrey ‘Hills’ are a short bike ride away for both road and mountain bike. The town has a lot of pubs and coffee shops with Kingston a short bus ride for very good shopping and also some evening entertainment, cinema, theatre and more pubs. The central part of Surbiton, walking distance to the station, can be pricey but areas heading towards Tolworth or Chessington can be cheaper likewise towards Kingston which has a lot of student accommodation for the university..
However personally in your situation I’d be more inclined to look at living closer to Chertsey. Have a look at Weybridge and Walton both of which have good rail links into London. The trade off for a slightly longer rail journey, maybe 10-15minutes longer, would be decreased rent and shorter commute in busy traffic. Epsom is also quite a nice little town, good rail links and surprisingly lively in the evenings, not sure about commuting from there to Chertsey though…