I have tried tons of gel pens. In terms of the best blue gel ink color, I think
Pilot wins. I love the 0.5mm version because the ink flow is generous and is
less likely to dry up or clog. I find with the thinner hi-tec-c points, the pen
tends to dry out or clog very easily. I can hardly finish a pen without it dying
in the middle.
With the 0.5mm, I don't have that problem.
If you like the color of this ink, I also suggest you to try the Pilot G-3 in
blue 0.38mm. That's an extremely good pen (I feel it's even better than the
hi-tec-c at a cheaper cost too). It might be 0.38mm, but it actually writes
equivalent or maybe slightly thicker than a 0.5mm hi-tec-c.