@ Bentley: You talk about people spouting lies, yet you use GT to try explaining cannon events in the anime/manga... Akira Toriyama had no part in GT except for the character design of Pan, making the movies of DBZ even more cannon than GT, which is just a big plot hole itself, as Baby Vegeta who fought on par with SSJ4 Goku couldn't blow up Earth with a full power super galick gun, something that even Saiyan saga Vegeta was capable of in DBZ.
IIRC, Frieza was never hit by a Taiyoken, but if he was, it was because he probably didn't know what it was. Cell used it against Piccolo to escape momentarily, but that was because he dropped his power level to unreadable levels, even to the Z-fighters(which he could only do because he was an android), after the brief opening that Solar flare gave him. Piccolo didn't have any sunglasses around, and didn't want to leave Cell because he would escape again, putting him in an un-winable situation. Being affected by Solar flare has nothing to do with speed, it has to do with your sight and resistance to... light, but if you can move faster than it and there just so happens to be a pair of sunglasses around, you can avoid it.
Now, while I admit DBZ characters can't fly for distances at lightspeed until later in the series(about the Frieza arc, like how Goku effortlessly traveled from one side of Namek, which was 10X the size of Earth, to the other in less than a second), they can fight at MFTL and sustain that speed for prolonged battles. An example is when Goku fought Vegeta and used Kaioken for the second time. He had an entire battle with Vegeta that lasted several manga pages, in the time it took for his heart to beat once. Here is proof.
http://mangawall.com/manga/dragon-ball/227/3
http://www.mangapark.com/manga/dbz/c232/6
http://www.mangapark.com/manga/dbz/c232/7
http://www.mangapark.com/manga/dbz/c232/8
http://www.mangapark.com/manga/dbz/c232/9
http://www.mangapark.com/manga/dbz/c232/10
http://www.mangapark.com/manga/dbz/c232/11
http://www.mangapark.com/manga/dbz/c232/12
http://www.mangapark.com/manga/dbz/c232/13
http://www.mangapark.com/manga/dbz/c232/14
Now, when Piccolo destroyed the moon, he did it with a simple ki blast. It took a two seconds for the explosion to show, and it takes light a little more than a second to travel from Earth to the moon, but it took two seconds for the explosion to be seen, so the blast was a little faster than light. This simple ki blast was shot by Piccolo without charging any ki. Now, when he used Special beam cannon the first time, he said it was his fastest, and most deadly technique. While this proves that it is faster than the beam he shot at the moon that was faster than light, Raditz was still able to dodge it.
Also, Tien used a technique that he claimed to make him able to punch faster than light. This is confirmed in the Daizenshuu. However, the Daizenshuu also states that Goku would have probably been able to dodge it, if it wasn't for Chiaotzu using his psychic abilities to immobilize him. In DBZ, flight speed is much slower than combat speed, so while someone like Superman may beat Goku in a race across the universe(if Goku wasn't using IT or SSJG and it was PC Superman or above), he couldn't keep up with his fighting speed, and couldn't measure to Goku's destructive capabilities(because PC Superman destroyed an asteroid belt with an uncontrollable sneeze, and Goku in base is quadrillions of times stronger in the Buu saga than someone who could destroy planets with a single attack, but that's not what I'm debating here).
Not to mention the fact that Goku and Tien easily dodged waves of photons shot by Dr. Gero, and as you should know, photons move at the speed of light. So... yeah.
@ BloodRain: I have read Haku's bio in the databook my friend owns just to solve this and I saw nothing that claimed Haku as light speed or faster. Also, Roshi was easily defeated by Tien. Goku was much faster and stronger than Roshi at that point, and was also faster and stronger than Tien by quite a bit. Tien even said that Goku was physically superior to him, but Tien simply had a larger arsenal of techniques which gave him the advantage and allowed him to win with luck.
Goku was known in Dragon Ball for his strength, but mostly for his tremendous speed. Roshi even commented while Goku fought Piccolo that Goku's best attribute has always been his speed and ability to vanish from even experienced eyes, including those of Kami. So, it isn't too difficult to believe that Goku can move faster than Tien or Roshi could see at that point.