LONG POST DISCLAIMER
I'm not here to comment on who our best XI was since 1877, as I wasn't old enough to see most of the names that are thrown around in this thread (I'm 24). However, if you ask me to name the best Australian XI I have seen (ie the best players at their peak) since I started watching cricket in the 1995/96 summer, it'd be
1 Hayden
2 Slater
3 Ponting
4 M Waugh
5 S Waugh (c)
6 Hussey
7 Gilchrist (wk)
8 Warne
9 Gillespie
10 MacGill
11 McGrath
Again, I repeat, this is a team of whom I believe were the best players at their peak. If you were to have all of those players at their peak and that side were to play the Indians this summer, barring bad weather, 4-0 would be the scoreline.
Regarding the bowlers, McGrath (best and most accurate fast bowler I've seen. Shaun Pollock, although not Australian, is not far behind in second place) and Warne (best spinner) are a shoe-in by a country mile, so no need for a long explanation of their selections. Regarding the other fast bowler, McGrath had many opening fast bowling partners (McDermott, Kasprowicz, Bichel, Gillespie, Flemming, Lee etc.), but at their peaks, Gillespie was the most lethal of the lot before he had his injury problems. I believe on the 1997 tour of South Africa, he clocked 155km/h, which was the fastest speed at the time (before Shoaib Akhtar and Brett Lee emerged a year or two later). He was more accurate than the other bowlers (reflecting in his average of 26), and such a shame that his career dramatically nosedived during the 2005 Ashes, and he was always on the outer with Ponting and the selectors after that. Furthermore, somewhat a bitter pill that although we played Bangladesh, he finished his career with a double century. To this day, I believe he shouldn't have been omitted from the side post-Ashes - that's a discussion for another time. Instead of chosing a third fast bowler, I put MacGill as the other bowler. Again, a shame he didn't play more tests, as Warne was the more marketable in the side. By the time he was seen as Warne's replacment post 2006/07 Ashes, his best years were well and truly behind him at 36 yrs of age. Being constantly in and out of the side makes it difficult for anyone to build any sort of consistency, but late 90s/early 00s, MacGill would've walked into any other international side as a spinner. He even outplayed Warne for the most part when they played together; Warne being notably omitted from the 4th test during the '99 tour of West Indies. Most memorable game for mine was the '99 SCG test. I've never seen anyone spin the ball as much as he did. I'm confident we would've won the 2005 Ashes had he been picked when McGrath got injured, as the Poms couldn't play leg-spin bowling for nuts, and Warne needed someone bowling from the other end to build sustained pressure.
Regarding the wicketkeeper, Healy was the better wicketkeeper. But, as a combination of wicketkeeping ability and batting ability, Gilchrist's batting gets him over the line. Gilly started showing signs of wear and tear during the 2005 Ashes, dropped many catches towards the end of his career. However, he took some rippers early on in his career: most notably being that 3rd test vs Pakistan at Perth in 1999. One of the best diving catches I've seen.
Regarding the batting, Ponting is a shoe-in at 3. At his peak, the best batsman we've had post-Bradman era. M Waugh had the best, most natural batting technique. One of the most naturally giften batsmen during his prime, but like Greg Blewett, someone who was ill-disciplined and whose statistics are not a fair reflection of his ability (averaging only 41, like Greg Matthews). I have no doubt that if this problem was rectified, he would've, like his brother, averaged at least 50. S Waugh...what more can you say? Like Border, one of only a few batsmen who played match-winning innings and always played for the team. He is the personification of grit and determination. Slater, I'd have just over Langer. Shame that his test career ended in acrimonious circumstances and surprising, didn't excel in the ODI format of the game as his aggressive style of batting was tailor-made for it. However, like M Waugh, lots of talent, but ill-discipline and impatience cost him dearly at times (getting out in the 90s 8 or 9 times). Add 8 or 9 more centuries to his test statistics would be a more accurate reflection of his true playing talent. At his peak, his timing of the ball was nearly as good as M Waugh's, and formed a formidable opening partnership with Tubby Taylor. Although Hayden/Langer achieved more records, in my opinion, the Taylor/Slater combination in the 90s gets the nod for me as they had to contend with better bowling attacks and less batter-friendly pitches. Haydos, well, his career didn't excel until he became a permanent fixture in the side around 2000/01, and he achieved a hell of a lot since then.
Hussey is, what I would say, the controversial selection in my XI. I know he's only played tests for 6 yrs, but from what I saw early in his career and the recent tour of Sri Lanka, is a very naturally gifted middle-order batsman. Mitchell Johnson gets a lot of credit for that Ashes test in Perth last year, but it was Hussey who got us out of trouble with his batting in that test. Hussey's batting was more valuable than Mitch's bowling and as a result, very unlucky not to get MOTM imo.
