#1 Finishing as group winners

Besiktas dominated Group G. They started off by winning their first three games and actually could've easily been through already with only four games played. Monaco denied them that with a 1-1 draw, even though they were outplayed most of the match.
Against Porto, Besiktas needed only a draw to secure a 1st place finish in the group and Talisca's third Champions League goal this season brought them the desired result. Now they can look forward to the Round of 16 draw in hope of maybe facing a weaker side.
There are many high calibre 2nd place finishers in the Champions League and some say that it doesn't even actually matter if you qualify as the winner or runner-up in your group, that the next opponent will be tough regardless, but it isn't true.
The group winners this season likely include PSG, Man City, Barcelona, Man United and other top teams. Among the runners-up, there's a chance there will be teams like Basel, Spartak Moscow and Shakhtar Donetsk. I know which teams I'd rather face if I was in charge of a team.
Besiktas has a good chance of facing an opponent of similar or even worse quality in the next round, and with the final only a couple of steps away when you reach the quarter-finals, anything can happen.