I've seen more rom-coms than I care to admit to, and provided you don't make a habit of watching this one on a weekly or even a monthly basis, I think My Best Friend's Wedding is one to place in your top ten. Obviously it's no When Harry Met Sally, but it's still way better than one of those Californian airhead movies.
Roberts' character has a prior claim on the affections of her old friend Mulroney, who shocks her into action when he announces he's marrying THE ONE. Roberts' knows she's the one and plots to steal Mulroney away from Cameron Diaz before the wedding. Rupert Everett plays the gay pal who is the voice of reason.
For all that this is a mainstream movie sometimes sickly sweet and silly, it also has many poignant and tender scenes - for example, when Mulroney and Roberts are on the ferry and again she misses her chance to claim him with a romantic gesture. Love is a competition where the boldest, the uninhibited win and no matter how deep the feelings of the others, they remain also-rans. What prevents this movie being too icky is Roberts' agreeably nasty attempts to undermine the almost cloying (but not quite) affection of Mulroney and Diaz. For all that Diaz's character is sweet like icing sugar, she still demonstrates a toughness and her determination to befriend her rival is clearly a maniuplative strategy to keep the "big-haired food critic" from becoming a threat. The showdown in the ladies' room was a late addition after focus groups complained Roberts was too evil to be sympathetic.
Everett is superb as Roberts' editor, very funny and very camp. Mulroney is also successful at conveying his character's inner turmoil and burgeoning jealousy. It's also nice to see a rom-com where instead of being reliant upon a pop soundtrack, the cast perform the songs themselves, admittedly in rather contrived circumstances.
Just FF the opening titles and you'll love this more than you might anticipate.