Singing Greeting Card: This is 6 dollars that will basically go straight in the garbage next week when the card comes down from the fridge (unless your dad is a hoarder, in which case, you should never buy him anything ever again). Plus, it's just awkward ... for both him and for everyone watching him open it, as he pretends to be amused by a static-filled semi-inaudible version of the Macarena.
Golf Balls: This is an exceptionally bad gift for your dad if he is not a golfer. However, if he IS a golfer and can afford to pay for tee times at various country clubs, he can certainly buy his own golf balls. Plus, nothing says "I love you, Dad" like ... balls? Skip it.
A Tie: I guess it depends on the age and/or personality of your father and whether or not he wears ties. But for argument's sake, let's say he does. He probably has at least a dozen of them in his closet from his last two birthdays and Father's Days ... all with tags still on them. (Note: this rule does not apply to metrosexual dads)
A Bathroom Book: Why do advertisers encourage us to purchase toilet readers? No one wants to visualize their father on the crapper, much less how he entertains himself during that time. This gives the concept of a "mushy gift" a whole new (gross) meaning. Avoid.
Shirt: Even if you think your dad could really use a new shirt... He'll probably only wear it once (ie. the next time you come over) and then go back to wearing the same old shirts he wears all the time. Also, see above re: ties.
Flip Cam: Yes, this is a very easy technology for anyone to use and it seems like a cool and different gift idea but, what exactly is your dad video taping? You will inevitably find this camera several years from now in a kitchen drawer, with a total of 2 minutes and 32 seconds of footage on it ... from Father's Day 2014.
Coffee Mug: Um, no.
Dating Profile: If you have a single dad, do not surprise him by creating an online dating profile for him. This is a big no no. I know it's progressive and he may even appreciate it but ... becoming your dad's pimp? That's just creepy.
So now that I have explained what NOT to do, let me give you a hint on what you could do: Spend time with your dad as much as possible throughout the year(s) and then you won't have to worry about buying him Hallmark's version of the "perfect" gift. Memories are priceless, timeless, and can't be exchanged for anything better!
Happy Father's Day.