Lightbrite – I think it should be both.I think both are important. One is probably more connected to Ahavas Hashem and the other to Yiras Hashem.
You need both. If you are only doing things for Yiras Hashem and reward in Olam Haba, you are missing the point, and you are missing out on a relationship with Hashem, and your Avodas Hashem is liable to be superficial.
On the other hand, if it is only about Olam Hazeh and Ahavas Hashem, while that is wonderful, you still need the Yiras Hashem part to keep you from stumbling. What happens when you are faced with temptation and Ahavas Hashem is not enough to keep you from giving in? What happens if at some point, c”v, you don’t feel so happy being Frum (hopefully just as a temporary stage while going through a hard time)?
In any case, as always, I am exceedingly impressed by your Ahavas Hashem, your love for Yiddishkeit, and your understanding that the main thing is our relationship with Hashem which takes place now and should be for its own sake and not for the sake of a reward. That is an attitude that some are missing, and I agree that it is a problem since this should be the main thing.
I think that it can be a matter of chinuch and/or personality. I think that for many years, I only had the Yiras Hashem/focus on Olam Haba aspect because somehow the other aspect had been lacking in my chinuch somehow. Boruch Hashem, I eventually picked it up, although of course, there is always room for growth.