It has been mentioned that snorting is your best ROA, but mainly because it is the easiest. Since IV'ing and freebasing don't seem to appease you either the option of plugging still remains open. I've never plugged cocaine, but I imagine it would be similar to IV cocaine minus the very very intense rush and ultimately short in duration (10-20 minutes). Insufflated cocaine is probably your best bet - Cocaine will take you somewhere with any ROA, it just varies by intensity and duration depending on the quality of the product and whatever ROA seems best for you.
In comparison to amphetamine (racemic-amphetamine) they both have similarities and differences (more differences tho'). And as previously stated both are subjective (varying from person to person). I've met people who enjoy amphetamine that think cocaine is garbage / vice versa. Both have stimulating qualities albeit depending on ROA. Amphetamine has a nice subtle euphoria and acts long in duration, where as cocaine is very rush oriented has more prominent euphoria and acts significantly shorter in duration making the desire to consume more even stronger.
I'll describe two different scenarios for you.
With amphetamine, assuming you have not taken a massive dose, can be mood-elevating with subtle euphoria that inhibits the desire to be productive. Amphetamine could be used recreationally as a social lubricant, a performance-enhancer (not sports think studies), or for just hanging around the house on a rainy day. Cocaine inspires prominent-euphoria that is extremely mood-elevating (depending on quality). Cocaine can be used as a great social lubricant as well such as party situations or just hanging with some 'bros' (lol), yet it can also be very isolating. I've met cocaine addicts that literally just sit around there house sweating bullets shooting cocaine non-step. I suppose the same can be said about both substances, again subjective (both are addictive and can potentially cause unwanted personal issues).
Amphetamine tolerance is notorious for developing rapidly. But for recreational purposes (given that you don't use frequently) one gram of amphetamine will take you miles, roads, and oceans further than cocaine. One gram of cocaine can be easily ran through in a day (or even a couple hours) depending on quality, how many are partaking, and re-dose compulsions. One gram of amphetamine (if not abused and depending on quality/ROA) can last quite a long time, possibly months with infrequent use.
You have to remember that both of these drugs act in very different ways. Read about the differences of MOA between
Amphetamine &
Cocaine.
A lot of what you are asking is preference based, and will yield no exact answers.
Both are interesting in their own ways. Just be responsible when using.
EDIT : One is not better than the other - it is subjective (important word here). I like both a lot, but choose to not use cocaine because I cannot use it responsibly. I hate putting personal thoughts in these post because it loses its objectivity.