With only a few games remaining in the season, there is much talk on which team has the easiest or hardest run-in, but mainly it is qualitative analysis which makes proper comparisons difficult. A better comparison is to evaluate the strength of the remaining opponents by calculating their average number of points.
Applying this to the four teams in contention for the fourth and final Champions League place shows that Tottenham's run-in, which includes Chelsea, Arsenal and Manchester Utd is only a point more difficult than Manchester City's, which includes Manchester Utd, Arsenal and Aston Villa. Liverpool and Aston Villa actually have significantly easier run-ins, but with so few games remaining it will be unlikely to find Villa or Liverpool in the Champions League next year:
                                                                        average points
             games  current  of remaining
             left   points   opponents
Man City      5      62       56
Tottenham     6      58       57
Liverpool     4      56       40
Aston Villa   6      54       40
At the other end of the table, despite Burnley's heroics last weekend their run-in is the toughest of the five teams in the relegation battle:
                                                                 average points
          games  current  of remaining
          left   points   opponents
Bolton     5      32       47
West Ham   4      31       48
Wigan      5      31       43
Burnley    4      27       50
Hull       5      27       45