The Rocket has decent food, is very lively and offers a great selection of real ales. The service is patchy - I suspect it just depends on who is working at the time. They do have a large screen for sports, but I found it difficult to watch from anywhere other than standing at the bar (lots of smaller TVs though, so I suppose that makes up for it). The garden area has plenty of street seating, but not particularly private and I was asked to move last time as they were taking a beer delivery. Fair enough ! I'd stick to the inside which has some very sociable seating configurations. The patrons seem like a heady mix of lager swilling trendy students from UCL, journeying folk between St Pancras/Euston enjoying a Guinness and wine sipping office workers between 5-7pm.
If you're after a few beers, meeting up with friends and one of the best Burgers on the Euston Road - then the Rocket should fit the bill for you.